眦部睑缘炎的可能病因为（）
A.屈光不正
B.视疲劳
C.莫一阿双杆菌感染
D.维生素B缺乏
E.睡眠不足
参考答案：C, D
The number of the people who _______ cars _______ increasing.
A．owns; are
B．owns; is
C．own; is
D．own; are
用DJ6型经纬仪测某竖直角，盘左读数76°45′12″，盘右读数283°14′36″，指标差应为（）。
A.06″
B.-06″
C.12″
D.-12″
