单项选择题

Many AIDS experts are not completely satisfied with results of the study because

A．only a limited number of chimpanzees are used for sampling the virus.
B．it is now extremely difficult to find chimpanzees that carry the virus.
C．the samples collected are from two different subspecies of chimpanzees.
D．it does not provide reliable evidence of the link between SIV and HIV-1.

<上一题目录下一题>

热门试题

单项选择题One of the results of grief mentioned in the passage is

A．loss of friendships.
B．diminished socializing.
C．vulnerability to disease.
D．loss of appetite.

单项选择题The researches reviewed in the passage suggest that

A．remarried men live healthier lives.
B．unmarried men have the longest life spans.
C．widowers have the shortest life spans.
D．widows are unaffected by their mates' death.

单项选择题According to researchers, Richard Nixon's death was

A．caused by his heart problems.
B．indirectly linked to his wife's death.
C．the inevitable result of old age.
D．an unexplainable accident.

单项选择题Helsing speculates that husbands suffer from the death of a spouse because they are

A．unprepared for independence.
B．incapable of cooking.
C．unwilling to talk.
D．dissatisfied with themselves.

单项选择题The passage states that while married couples can prepare for grieving by

A．being self-reliant.
B．evading intimacy.
C．developing habits.
D．avoiding independence.