夏季，长江中下游地区会出现“伏旱”天气。造成这种现象的天气系统是
A．A
B．B
C．C
D．D
答案：B
The doctor told Mary that too much ________ to the sun is bad for the skin.[ ]
A. exposure
B. extension
C. exhibition
D. expansion
当大开颌运动时，下颌下降约为( )以上。
A．0.5cm B．1.0cmC．1.5cm D．2.0cmE．2.5cm
