直线l外有一点A，点A到l的距离是5cm，点P是直线l上任意一点，则[ ]
A．AP＞5cm
B．AP≥5cm
C．AP=5cm
D．AP＜5cm
答案：B
The population of China___ to many times what it was in 1949, and most of its population ___ farmers.
A．have grown; are
B．have grown; is
C．has grown; is
D．has grown; are
代谢性碱中毒常伴发（）。
A.低钾血症
B.低镁血症
C.高钾血症
D.低钠血症
E.高钠血症
