4．The Chinese were the first to use fingerprints to identify（识别） people．They saw that fingerprints were different．When people signed（签名） important papers，they put their fingerprints on them．
Skin is an organ．It is the largest organ of the body．There are some things about skin that are the same in everyone．
•Everyone has a dermis．This is the inner layer （内层） of skin．It is alive．
•Everyone has an epidermis．This is the part of the skin that you see．It is made up of dead cells．
•Everyone has pores in his or her skin．Pores are tiny openings in the skin．Leaving the body from pores，sweat（汗） helps to cool the body when the body becomes too hot．
All people have different in their skin，too．Look at the tip of your finger．Can you see tiny lines？The lines form a pattern．That is your fingerprint．There are names for general patterns in fingerprints．But no two people have exactly the same pattern．Only you have the pattern on your finger．
Imagine that a thief leaves fingerprints on a window．Later，the police find the fingerprints．They fingerprint the person they think is the thief．If the prints match，the police have their thief．
71．C shows us a picture of a fingerprint．
A．
B．
C．
72．B shows us the right names of different parts of the skin．
A．
B．
C．
73．Sweat comes out of theB．
A．dermis B．pore C．epidermis
74．We learn from the passage that fingerprints are helpful toA in their jobs．
A．policeman B．doctors C．teachers
75．Which of the following statement is TRUE according to this passage？
A．You can often see fingerprints which are put on the daily newspaper．
B．Fingerprints formed by different lines are the largest part of the body．
C．All people have fingerprints which are different from one another．
