搜题请搜索小程序“爱下问搜题”
问题 选择题

复数6+5i共轭复数的虚部为（　　）

A．-5i

B．5i

C．-5

D．5

答案

复数6+5i共轭复数为 6-5i，而 6-5i 的虚部等于-5，∴复数6+5i共轭复数的虚部为-5．

故选C．

填空题

用所给单词的适当形式填空。

1. —What's the date today?

     —It's the______ (twenty) of May.

2. Thank you for ______ (invite) me to your party. But I can't accept your______ (invite)

     because I have a lot of work to do.

3. Please keep quiet. He______ (try) the piano.

4. This is my______ (brother)  new shirt.

5. He has much work______ (finish).
查看答案
单项选择题

对LFP-901A型微机保护装置主保护中的电压回路断线闭锁，只要三相电压相量和大于（），即发断线闭锁信号。

A.5V

B.6V

C.8V

D.9V
查看答案