单项选择题

DNA fingerprinting can be unreliable when ________.

A．the methods used for 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

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热门试题

单项选择题

What is the passage mainly about

A．What the poverty line is.
B．Why some people live below the poverty line.
C．To find how to reduce poverty.
D．To study the reasons of poverty in order to solve the problem of poverty.

单项选择题

According to the passage, why can't most of the American poor people find a good job

A．Because they are too lazy to work.
B．Because they lack professional skills.
C．Because most of the American poor people are the young children and the old people.
D．Because they have many mental problems.