世界陆地的最高点是珠穆朗玛峰，最低点则位于中东地区的[ ]
A．贝加尔湖
B．里海
C．死海
D．咸海
答案：C
They didn't watch TV _______ they finished their homework. [ ]
A. when
B. as
C. while
D. until
硬肿症血气分析可见（）
A.血pH正常
B.血pH降低
C.PaO增高
D.PaO降低
E.PaCO增高
