【判断题】节点用来表示两条相交的导线是否有电气连接。()
【判断题】保护接地是指为了人身安全的目的,将电气装置中平时不带电,但可能因绝缘损坏而带上危险的对地电压的外露导电部分与大地作电气连接。
【单选题】the bedroom need to be cleaned.
A.
Either the classroom or
B.
Neither the classroom nor
C.
Both the classroom and
D.
Not only classroom but also
【单选题】Which of the following was not written by Washington Irving?
C.
The Legend of Sleepy Hollow.