使用“导通法”注意事项
参考答案:
要先断开操作电源,即拔下该回路小保险。要注意被测元件是否有旁路,否则有可能会误判断,因此必须将旁路拆开。一般用来检查电流回路。
So difficult ___it to work out the problem that I decided to ask Tom for advice.
A.I did find
B.did I find
C.I have found
D.have I found
具有3个结点的二叉树有( )。
A.2种形态
B.4种形态
C.7种形态
D.5种形态