[单项选择]According to this passage, nobody knows for sure _________.


A. how people began to use fire
B. why people began to use fire
C. how to make a fire with matches

[单项选择]According to this passage, nobody knows for sure _________.

[单项选择]Nobody knows, ______


A. does nobody
B. does one
C. does he
D. do they

[单项选择]Nobody knows why there are so few women at the ______ of movies.
A. helm
B. seat
C. control
D. reign

[单项选择]Nobody knows the date of arrival, ______ ( )

[单项选择]According to the passage, we can be sure that______.


A. organised crimes rampaged in the US during the era of Prohibition
B. organised crime can profit more from handling and reselling of stolen goods than from trade in pornographic literature
C. special measures have been taken to crack down any form of illegitimate activities
D. all of the above

[单项选择]

Passage Three
Everyone knows the small insects called mosquito. It is possible to find mosquitoes in almost every part of the world except in the places where it is extremely cold or where it is very dry. During the summer, it is almost certain that you can find many mosquitoes near swamps (沼泽), ponds, and lakes.
Mosquitoes have an interesting life cycle. The female mosquito bites a person or animal in order to get some blood. She needs this blood before she can lay her eggs. Second, she flies to an area of water and deposits (存放),40 her eggs in the water. In a few days the eggs open, and the baby mosquitoes, called larvae, come out. In a short time, they will be mature and fly away.
It is interesting to note that only the female will bite for blood. She has a special mouth which can go into an animal’s skin or a person’s skin. On the other hand, the male mosquito can only drink plant juices with his mouth.

Only the （） will bite for
A. male
B. baby mosquitoes
C. mosquito
D. female