Last year the number of students who graduated with a driving licence reached 200,000, a(n) () of 40,000 per year.

单项选择题It is reported that some scientists in the United States have found a new ______ for cancer.

单项选择题Which of the following best explores American myth in the 20th century

单项选择题Betty advised me to label our luggage carefully in case it gets______in transit.

单项选择题There is a ______ of impatience in the tone of his voice.

单项选择题Does the TV say ______ happened in Iraq every day

单项选择题Gun control is a subject ______ Americans have argued for a long time.

单项选择题Bats are surprisingly long-lived creatures, some ______ a life span of around 20 years.

单项选择题As a salesman, he works on a (an) ______ basis, taking 10% of everything he sells.

单项选择题I'm not quite sure how to get there. I'd better______a map.

单项选择题—I'm going to study engineering in Tsinghua University tomorrow. —______.