找考题网-背景图
单项选择题

The attitude of the Federal Bureau of Investigation shows that ______.

A．enough data are yet to be collected from various ethnic groups to confirm the unlikelihood of two DNA samples coming from two individual members
B．enough data of DNA samples should be collected to confirm that only .DNA samples from the same person can match
C．enough data are yet to be collected from various ethnic groups to determine the likelihood of two different DNA samples coming from the same person
D．additional samples from various ethnic groups should be collected to determine that two DNA samples are unlikely to come from the same person
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热门试题

单项选择题According to the passage, DNA fingerprinting can be unreliable when ______.

A．the methods used of blood-cell calculation are not accurate
B．two different individuals of the same ethnic group may have the same DNA fingerprinting pattern
C．a match is by chance left with fingerprints that happen to belong to two different individuals
D．two different individuals leave two DNA samples

单项选择题To geneticists like Lewontin and Hartl, the current method ______.

A．is not so convincing as to exclude the likelihood that two DNA samples can never come from two individuals
B．is beyond dispute because two individuals of the same ethnic group are likely to have the same DNA pattern
C．is not based on adequate scientific theory of genetics
D．is theoretically contradictory to what they have been studying

单项选择题The National Academy of Sciences holds the stance that ______.

A．DNA testing should be systematized
B．only authorized laboratories can conduct DNA testing
C．the academy only is authorized to work out standards for testing
D．the academy has the right to accredit laboratories for DNA testing

单项选择题We learn from the passage that ______.

A．foreign language requirements for the Ph. D. do not vary in difficulty among universities
B．meeting foreign language requirements for the Ph. D. is the most frequent reason for dropping out
C．it is an essential part of many Ph. D. programs to meet foreign language requirements for the Ph.D.
D．meeting foreign language requirements for the Ph. D. is more difficult for the science candidate than for the humanities candidate

单项选择题It can be inferred from the passage that ______.

A．there are 1,000 positions for the Ph. D. s
B．the high rate of dropouts is because the salary for dropouts is too high
C．the high rate of dropouts lies in the fact that the salary for Ph. D. is too low
D．the reason why so many Ph. D. candidates drop out is that academic requirement is too high for them