单项选择题

The biggest worry that the researchers now have is

A．more and more wild chimpanzees are being slaughtered.
B．AIDS virus is difficult to be killed and controlled.
C．it is not easy to repair people's deficient immune systems.
D．many dangerous viruses are being transmitted to humans.

<上一题目录下一题>

热门试题

单项选择题

The significance of the finding is that

A．people now know the number of chimpanzees is much smaller than expected.
B．it may make it possible for scientists to discover new ways of treating AIDS.
C．it proves some deadly human diseases can also be transmitted to wild animals.
D．it will soon help the scientists develop a vaccine that prevents the AIDS virus.

单项选择题

According to Hahn, all the following increase the transmission of AIDS virus EXCEPT

A．hunting and killing more chimpanzees.
B．more champ hunters moving to cities.
C．people's changed sexual behaviours.
D．travelling to more African countries.