一个三角形三个角的比，5：3：1 分则这个三角形是________三角形
2018年12月，张阿姨把4000元的存入银行，定期三年，年利率是2.75%到期后，应得利息______元.
Don’t leave anyone ________ (back/ behind). We are in a group.
Tomorrow we’ll have a school trip. But Sally _______ (has to/ had to) stay at home to look after her sick mother.
__________ (Be quick / Don't worry), Tom! You have a lot of time for your work.
We all want to live in a city with __________ (many cars / fresh air).
There are many interesting places in Australia. _______________ (The Great Barrier Reef / Stonehenge) is a good place to visit.
Washing hands _____ (before / after) dinner is a good habit.
Look! An old lady ________ (carries / is carrying) a big bag on her back.
Food ______ (safely / safety) is very important for all of us.
At the Dragon Boat Festival people usually eat ________________ (rice dumplings /dumplings).
