单项选择题

Air moves under such conditions that______.

A．there is air pressure
B．the air is heavy
C．air pressure doesn't remain the same all the time
D．air comes up and down
<上一题 目录 下一题>
热门 试题

单项选择题
What were the primary uses of the horse for early man
A．For food.
B．For power.
C．To make money.
D．To work for him.
单项选择题
What might be the author's possible purpose in writing this passage
A．To tell readers that horse appeared earlier than human being.
B．To inform us that horses can help us a lot.
C．To introduce the history and characteristics of horses.
D．To introduce the primitive homes to modem man.
相关试题