题目内容：

The skin which covers the tips of the fingers and thumbs is crossed by numerous ridges (隆起) arranged in different patterns. These patterns are permanent from birth and remain exactly the same throughout a person's life, even when the skin becomes wrinkled and cracked as a result of old age. Such patterns are never passed on from parents to children, and no one in the world has the same patterns as anyone else. Even identical twins have different sets of fingerprints. As a result, fingerprints offer a most useful and foolproof way of identifying people. Any ridged part of the hand and the foot may be used as a means of identification, but finger impressions are usually preferred since they can be taken easily and quickly.

Fingerprints are classified in the ways: by general shapes and contours(轮廓), by the finger positions of the pattern-types, and by size (often measured by counting the ridges in the loops). Every set of fingerprints has different “ridge characteristics” (i. e. the print of each separate finger is different from that of all the other fingers), which belong to one of four basic groups: arches, loops, whorls and composites. All fingerprints can then be divided into 1, 024 groups. By using details in the patterns above, these 1, 024 groups can be further divided into thousands of smaller groups, thus making it possible to find a particular set of fingerprints in a few minutes.

1.According to this passage, the true statement about human fingerprints is that ____.

A．people's fingerprints sometimes can be passed on from parents to children

B．people’s fingerprints are unique but identical twins may have the same fingerprints

C．using fingerprints is the only way to identify people

D．people's fingerprints will not change in all their lives

2.We prefer to use fingerprints to identify people because ____.

A．we can never find the same set of fingerprints among human beings

B．finger impressions can be taken easily and quickly

C．fingerprints offer a most useful and foolproof way of identifying people

D．all of the above

3.The word “foolproof” (Line 7, Para. 1) most probably means ____.

A．that is permanent　                     B．that is acceptable

C．that can not go wrong　                  D．that is not foolish

4.About the classification of fingerprints, which is TRUE? ____.

A．Fingerprints can be classified in three ways

B．All fingerprints can be divided into 1, 024 groups and can not be divided further

C．It is not easy to find a particular set of fingerprints in a short time

D．People can not classify the fingerprints in an effective way