凡黏膜部发生浅表溃疡，呈凹形有腐肉而脓液不多的称为
A．溃疡B．疳C．溃烂D．疮疡E．疮
参考答案：B
Each player tried his best to _________ the game.
A．beat
B．defeat
C．catch
D．win
大气对雷达波的衰减主要是因为分子对电磁波的散射造成的。
