问题

What will people die of in 100 years? If you think that is a simple question, you ______ attention to the revolution taking place in biotechnology

A:have not been paying
B:had not been paying
C:were not paying
D:will not be paying

正确答案是：

同类题型

could hardly see the words onthe blackboard, ________

d man came ___ to the railwaystation, only ___ the train was slowly pulling out of the station.

144 The reason why the two _____ cannotspeak _____ language is that they were born in America and were brought up in aJapanese family

I am sorry. I __________ thedictionary in my home.

Thank you for hclping me with my homework.—– .