容器接地设施的检查，通常包括如下几方面：（）
A.检查导线是否断股
B.检查联接处是否良好
C.对埋地杆的对地电阻率进行测量
参考答案：A, B, C
The research mainly deals with the difficulty the students have _____ their attention on their study all the time. [ ]
A. to focus
B. to be focused
C. focusing
D. focused
瞳孔的直径为：
A．1mm
B．1-2.5mm
C．2.5-4mm
D．4-5.5mm
E．以上都不对
