问题补充：
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
答案：
(答案→)A. have not been paying
B. had not been paying
C. were not paying
D. will not be paying
解析：句意：100年之后，人类将会死于什么呢？如果你认为这个问题很简单，那么你肯定没有注意在生物技术方面所发生的变革。本句根据语境表示动作从过去开始一直延续到现在还有可能继续进行下去，故用现在完成进行时态，故选A
