After ten years of being a housewife and a mother,Carol could not stand it any longer.Then,one?morning,just after her two daughters had gone to school,she saw an advertisement（广告）in the pa-per.She phoned,and was asked to come to an interview（面谈）that very afternoon.
Mr.Hollins,who interviewed her,was a young man about 24 in a blue suit.There was a hard?look in his eye and he talked very fast.He told her she would be required to stop men between the?ages of 21 and 50 and ask them several questions designed to determine what men think of deodor-ants（除臭剂）.The information was to be recorded and she would be paid according to the number?of complete interviews she had.
When Carol asked which factory the research was for,she was told that was not important.Last?of all,before she began she would have to attend a one-day training.Carol accepted.After the train-ing,which was only about how to write down the answers correctly in a form and how to put the ques-tions,Carol found herself in the center of town at 9:30 in the morning.She soon found out that get-ting the information was really not all that easy.
First,she stopped a man who refused to answer any questions because he had no time.Next,a?man told her it was none of her business whether he used deodorants or not.Then she interviewed a?man who was hard of hearing and,instead of answering her questions,began asking her all sorts of?his own.Finally,Carol found a young man with a pleasant smile on his face.He was coming towards?her slowly and seemed ready to talk.He looked surprised when she put her first question."I′m doing?a research,too.It′s about soap powders,"he said.
Before Carol started to work,she learned how to__________.
通过第三段第四句可知Carol通过这种培训，基本掌握了如何做问卷调查，因此可确定选c项。
