Space is a dangerous place, not only because of meteors but also because of rays from the sun and other stars. The atmosphere again acts as our protective blanket on earth. Light gets through and this is essential for plants to make the food which we eat. Heat, too, makes our environment endurable. Various kinds of rays come through the air from outer space, but enormous quantities of radiation from the sun are screened off. As soon as men leave the atmosphere they are exposed to this radiation. But their spacesuits or the walls of their spacecraft, if they are inside, do prevent a lot of radiation damage.
Radiation is the greatest known danger to explorers in space. The unit of radiation is called “rem”. Scientists have reason to think that a man can put up with far more radiation than 0.1 rem without being damaged; the figure of 60 rems has been agreed on. The trouble is that it is extremely difficult to be sure about radiation damage－a person may feel perfectly well, but the cells of his or her sex organs may be damaged, and this will not be discovered until the birth of deformed （畸形的） children or even grandchildren. Missions of the Apollo flights have had to cross belts of high radiation and, during the outward and return journeys, the Apollo crew accumulated large amount of rems. So far, no dangerous amounts of radiation have been reported, but the Apollo missions have been quite short. We simply do not know yet how men are going to get on when they spend weeks and months outside the protection of the atmosphere, working in a space laboratory. Drugs might help to decrease the damage done by radiation, but no really effective ones have been found so far.
According to the first paragraph, the atmosphere is essential to man in that ____.（ ）
由第一段可知，由于流星和来自太阳及其他星体的射线，使得宇宙空间成为危险之地，而大气层可以充当地球的保护毯。因此，大气层在保护人类不受有害射线的辐射方面至关重要，故选A。
学校将组织一次英语演讲比赛，打算邀请外教（John）来做评委。请你（Li Yuan）给他写一封e—mail，内容包括：?
·邀请他担任评委（judge）；?
·告知他比赛安排（如：时间、地点等）；?
·希望他赛后进行点评；?
·期待他能接受邀请。
A.I am free on Sunday.
B.See you then!
C.Where are you planning to go?
D.No,thanks.
E.I need a break!
F.Would you like to join us?
G.That is a lovely place.
H.When shall we leave?
Daniel:How are you doing,Linda?
Linda:To be honest,I am really tired of my
Heahh care experts have long drawn attention to the problems of eating too much sah．There isstrong evidence that a diet high in salt can lead to raised blood pressure．Since high blood pressure is amajor factor in heart disease．it makes sense to cut down on the salt people eat．?
In the past，food contained very little salt，and people added it to their food at the table．Very fewpeople ?add ?salt this ?way ?nowadays．However，the ?salt ?content ?of processed ?foods has ?gone ?updramatically．It’s now estimated that over three．quarters of the salt in the average diet comes fromprocessed foods，eaten without our being aware of it．?
Salt is added to food partly to extend shelf-life．but more often it’s dropped in to make up for theflavor lost in the manufacturing process．This is especially true of ready meals and highly processedfoods．but it’s also true of such basic food as biscuits，soups，and even bread．Much mass—producedbread，for instance．contains so much salt．half a gram for every hundred grams of bread--that it’sofficiallv classified bv the UK government as high——salt food．Salt has to be added to the bread becausefast Droduetion cuts down the time for the flavor to develop．Without added salt，the bread would tastelike paper．?
In the UK，the government has launched a campaign to cut down on the salt people eat．The UK Food Standards Agency argues that nearly half of the UK’s population eat too much salt—9．5 9 a day onaverage．Its aim is to bring down the average t0 69 a day．The idea is to cut the salt content in 85 keyfood categories such as bread．meat．and cakes．?
?What is the passage mainly about?
Heahh care experts have long drawn attention to the problems of eating too much sah．There isstrong evidence that a diet high in salt can lead to raised blood pressure．Since high blood pressure is amajor factor in heart disease．it makes sense to cut down on the salt people eat．?
In the past，food contained very little salt，and people added it to their food at the table．Very fewpeople ?add ?salt this ?way ?nowadays．However，the ?salt ?content ?of processed ?foods has ?gone ?updramatically．It’s now estimated that over three．quarters of the salt in the average diet comes fromprocessed foods，eaten without our being aware of it．?
Salt is added to food partly to extend shelf-life．but more often it’s dropped in to make up for theflavor lost in the manufacturing process．This is especially true of ready meals and highly processedfoods．but it’s also true of such basic food as biscuits，soups，and even bread．Much mass—producedbread，for instance．contains so much salt．half a gram for every hundred grams of bread--that it’sofficiallv classified bv the UK government as high——salt food．Salt has to be added to the bread becausefast Droduetion cuts down the time for the flavor to develop．Without added salt，the bread would tastelike paper．?
In the UK，the government has launched a campaign to cut down on the salt people eat．The UK Food Standards Agency argues that nearly half of the UK’s population eat too much salt—9．5 9 a day onaverage．Its aim is to bring down the average t0 69 a day．The idea is to cut the salt content in 85 keyfood categories such as bread．meat．and cakes．?
Which of the following is classified as high—salt food by the UK government?
Heahh care experts have long drawn attention to the problems of eating too much sah．There isstrong evidence that a diet high in salt can lead to raised blood pressure．Since high blood pressure is amajor factor in heart disease．it makes sense to cut down on the salt people eat．?
In the past，food contained very little salt，and people added it to their food at the table．Very fewpeople ?add ?salt this ?way ?nowadays．However，the ?salt ?content ?of processed ?foods has ?gone ?updramatically．It’s now estimated that over three．quarters of the salt in the average diet comes fromprocessed foods，eaten without our being aware of it．?
Salt is added to food partly to extend shelf-life．but more often it’s dropped in to make up for theflavor lost in the manufacturing process．This is especially true of ready meals and highly processedfoods．but it’s also true of such basic food as biscuits，soups，and even bread．Much mass—producedbread，for instance．contains so much salt．half a gram for every hundred grams of bread--that it’sofficiallv classified bv the UK government as high——salt food．Salt has to be added to the bread becausefast Droduetion cuts down the time for the flavor to develop．Without added salt，the bread would tastelike paper．?
In the UK，the government has launched a campaign to cut down on the salt people eat．The UK Food Standards Agency argues that nearly half of the UK’s population eat too much salt—9．5 9 a day onaverage．Its aim is to bring down the average t0 69 a day．The idea is to cut the salt content in 85 keyfood categories such as bread．meat．and cakes．?
What can be inferred about people’s use of salt in the past?
Heahh care experts have long drawn attention to the problems of eating too much sah．There isstrong evidence that a diet high in salt can lead to raised blood pressure．Since high blood pressure is amajor factor in heart disease．it makes sense to cut down on the salt people eat．?
In the past，food contained very little salt，and people added it to their food at the table．Very fewpeople ?add ?salt this ?way ?nowadays．However，the ?salt ?content ?of processed ?foods has ?gone ?updramatically．It’s now estimated that over three．quarters of the salt in the average diet comes fromprocessed foods，eaten without our being aware of it．?
Salt is added to food partly to extend shelf-life．but more often it’s dropped in to make up for theflavor lost in the manufacturing process．This is especially true of ready meals and highly processedfoods．but it’s also true of such basic food as biscuits，soups，and even bread．Much mass—producedbread，for instance．contains so much salt．half a gram for every hundred grams of bread--that it’sofficiallv classified bv the UK government as high——salt food．Salt has to be added to the bread becausefast Droduetion cuts down the time for the flavor to develop．Without added salt，the bread would tastelike paper．?
In the UK，the government has launched a campaign to cut down on the salt people eat．The UK Food Standards Agency argues that nearly half of the UK’s population eat too much salt—9．5 9 a day onaverage．Its aim is to bring down the average t0 69 a day．The idea is to cut the salt content in 85 keyfood categories such as bread．meat．and cakes．?
What is the main reason for reducing salt in food?
My boyfriend really enjoyed canoeing (划独木舟), and it took me a while to finally persuade himto take me on a canoe trip. Despite his great skill, he was nervous about my safety and described manyterrible situations that could happen. "They could also not happen," I said. I wanted to prove that I wastough and capable of adventuring.?
This would be a romantic adventure. We would row the canoe on the lake under a beautiful bluesky. I was confident it would all go according to plan.?
It did not go as planned. Instead,?it all went downhill. We hit a headwind (逆风). The flies werethe worst. An unknown animal outside our tent in the night forced us to get up twice to scare it away.We walked through knee-deep mud; we moved around so many fallen trees that we lost the wayfrequently. We had an unexpected thunderstorm on our second night. We hid in our tent from the bugs(虫子), too tired and bitten to even hold each other. When we were finally back in the car, my skinwas hot and angry with bug bites, I had barely slept in 72 hours and I had an injury on my forehead fromhitting it on the canoe.?
Yet I realized that I wanted to do it all again. Because I swam in a lake so warm it felt like asummer pool. ?I ate lunch on an island with the most beautiful pine trees. ?I' d also never beforeappreciated how thunder can make the ground tremble. I know why my boyfriend loves canoeing somuch. It' s for the challenge, the space, and the beauty of moving forward with your own two hands ina place of natural wonder. He didn' t say "I love you. " He said I was a good partner. I' ve foundsomething that I really like to do. That' s the more important thing.?
What would be the best title for the passage?
My boyfriend really enjoyed canoeing (划独木舟), and it took me a while to finally persuade himto take me on a canoe trip. Despite his great skill, he was nervous about my safety and described manyterrible situations that could happen. "They could also not happen," I said. I wanted to prove that I wastough and capable of adventuring.?
This would be a romantic adventure. We would row the canoe on the lake under a beautiful bluesky. I was confident it would all go according to plan.?
It did not go as planned. Instead,?it all went downhill. We hit a headwind (逆风). The flies werethe worst. An unknown animal outside our tent in the night forced us to get up twice to scare it away.We walked through knee-deep mud; we moved around so many fallen trees that we lost the wayfrequently. We had an unexpected thunderstorm on our second night. We hid in our tent from the bugs(虫子), too tired and bitten to even hold each other. When we were finally back in the car, my skinwas hot and angry with bug bites, I had barely slept in 72 hours and I had an injury on my forehead fromhitting it on the canoe.?
Yet I realized that I wanted to do it all again. Because I swam in a lake so warm it felt like asummer pool. ?I ate lunch on an island with the most beautiful pine trees. ?I' d also never beforeappreciated how thunder can make the ground tremble. I know why my boyfriend loves canoeing somuch. It' s for the challenge, the space, and the beauty of moving forward with your own two hands ina place of natural wonder. He didn' t say "I love you. " He said I was a good partner. I' ve foundsomething that I really like to do. That' s the more important thing.?
Which of the following happened during their canoe trip?
My boyfriend really enjoyed canoeing (划独木舟), and it took me a while to finally persuade himto take me on a canoe trip. Despite his great skill, he was nervous about my safety and described manyterrible situations that could happen. "They could also not happen," I said. I wanted to prove that I wastough and capable of adventuring.?
This would be a romantic adventure. We would row the canoe on the lake under a beautiful bluesky. I was confident it would all go according to plan.?
It did not go as planned. Instead,?it all went downhill. We hit a headwind (逆风). The flies werethe worst. An unknown animal outside our tent in the night forced us to get up twice to scare it away.We walked through knee-deep mud; we moved around so many fallen trees that we lost the wayfrequently. We had an unexpected thunderstorm on our second night. We hid in our tent from the bugs(虫子), too tired and bitten to even hold each other. When we were finally back in the car, my skinwas hot and angry with bug bites, I had barely slept in 72 hours and I had an injury on my forehead fromhitting it on the canoe.?
Yet I realized that I wanted to do it all again. Because I swam in a lake so warm it felt like asummer pool. ?I ate lunch on an island with the most beautiful pine trees. ?I' d also never beforeappreciated how thunder can make the ground tremble. I know why my boyfriend loves canoeing somuch. It' s for the challenge, the space, and the beauty of moving forward with your own two hands ina place of natural wonder. He didn' t say "I love you. " He said I was a good partner. I' ve foundsomething that I really like to do. That' s the more important thing.?
What does the sentence“it all went downhill”in Paragraph 3 mean?
My boyfriend really enjoyed canoeing (划独木舟), and it took me a while to finally persuade himto take me on a canoe trip. Despite his great skill, he was nervous about my safety and described manyterrible situations that could happen. "They could also not happen," I said. I wanted to prove that I wastough and capable of adventuring.?
This would be a romantic adventure. We would row the canoe on the lake under a beautiful bluesky. I was confident it would all go according to plan.?
It did not go as planned. Instead,?it all went downhill. We hit a headwind (逆风). The flies werethe worst. An unknown animal outside our tent in the night forced us to get up twice to scare it away.We walked through knee-deep mud; we moved around so many fallen trees that we lost the wayfrequently. We had an unexpected thunderstorm on our second night. We hid in our tent from the bugs(虫子), too tired and bitten to even hold each other. When we were finally back in the car, my skinwas hot and angry with bug bites, I had barely slept in 72 hours and I had an injury on my forehead fromhitting it on the canoe.?
Yet I realized that I wanted to do it all again. Because I swam in a lake so warm it felt like asummer pool. ?I ate lunch on an island with the most beautiful pine trees. ?I' d also never beforeappreciated how thunder can make the ground tremble. I know why my boyfriend loves canoeing somuch. It' s for the challenge, the space, and the beauty of moving forward with your own two hands ina place of natural wonder. He didn' t say "I love you. " He said I was a good partner. I' ve foundsomething that I really like to do. That' s the more important thing.?
Why did the writer want to have a canoe trip with her boyfriend?
