搜题请搜索小程序“爱下问搜题”
问题 单项选择题

关于避孕药，下列哪项不正确

A．避孕药是人工合成的甾体激素，于1963年开始用于我国

B．18甲基炔诺酮属于孕酮衍生物

C．女用避孕药多数是雌孕激素复合制剂

D．口服避孕药分为长效和短效

E．紧急避孕药有激素类和非激素类两类

答案

参考答案：B

连词成句

连词成句。

1. you, do this, year, to, what, going, are

                                                                                                           

2. piano, brother, take, and, to, going, I, my, lessons, are 

                                                                                                           

3. you, do, to, get, part-time, a, want, job

                                                                                                           

4. many, kids, parents, their, want, with, to, better, communicate 

                                                                                                           

5. fit, lots, keep, of, to, people, want, do, they, sports, because

                                                                                                           

查看答案
单项选择题

当断路器三相跳、合闸不同期超过标准时，对运行的危害是（）

A.变压器合闸涌流增大

B.断路器的合闸速度降低

C.断路器合闸速度降低，跳闸不平衡电流增大

D.产生危害绝缘的操作过电压，并影响断路器切断故障的能力
查看答案