在单相桥式整流电路中,设变压器二次电压有效值为U2,则每只二极管所承受的最高反向电压

题型:单项选择题

问题:

在单相桥式整流电路中,设变压器二次电压有效值为U2,则每只二极管所承受的最高反向电压是()。

A. 2U2

B.U2

C.U2

D. 1/2U2

考点:电动装卸机械修理工电动装卸机械修理工综合练习电动装卸机械修理工综合练习题库
题型:单项选择题

第一节:单词拼写(每小题1分,满分10分)

小题1:The car was so badly damaged that it couldn’t be repaired and had to be _____(放弃) as a total loss.

小题2:One’s appearance is not _______ (有关的) to whether he can do things well.

小题3:We believe that young children should never ________(反驳) what their parents say.

小题4:My first two shots missed the ______(靶).

小题5:There is no _______ (通路)to the street through that door.

小题6:Lily, could you r______ me a latest movie which is popular among your people?

小题7:I have a______ myself to the new work environment.

小题8:The new employees were presented to the rest of the s______ at the company’s meeting.

小题9:Terry was chosen by our class to p_______ in the sports meeting in the school.

小题10:The new discovery is b_____ to be of great benefit to humans,” the researcher said confidently.

题型:单项选择题

2010年底,全国高速公路里程为7.41万公里,居世界第二位,比“十一五”规划目标增加9108公里,其中,国家高速公路5.77万公里,比上年末增加0.54万公里。“五纵七横”12条国道主干线提前13年全部建成。全国有11个省份的高速公路里程超过3000公里。

2010年底,高速公路里程超过全国总里程5%的省份有几个()

A.5

B.6

C.7

D.8

题型:单项选择题

甲状腺功能亢进症最主要的病因是()

A.放射线过多

B.对链球菌变态反应

C.直接病毒感染

D.直接细菌感染

E.自身免疫性

题型:单项选择题

---Your sister looks upset.

---Yes, I’d rather I _____ her the bad news.

A.didn’t tell

B.don’t tell

C.hadn’t told

D.wouldn’t told

题型:单项选择题

斯宾塞是如何理解生物有机体与社会有机体间的不同的?

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