光电耦合器要求输出功率大时应选用()A.光敏三极管 B.达林顿管 C.IC光耦合器

题型:单项选择题

问题:

光电耦合器要求输出功率大时应选用()

A.光敏三极管

B.达林顿管

C.IC光耦合器

D.光敏二极管

考点:动力与电气工程电力系统电力系统题库
题型:单项选择题

第II卷 (共三节,满分50分)

第一节:单词填空(共10小题,每题1分)

第一小节根据句意和所给单词的首字母(或汉语提示)填空。

71. The students who were t____________ in the burning building were frightened.

72. We were r____________ from the sinking ship by a passing boat.

73. It took a long time for him to ____________(康复) from a bad cold.

74. After g_____________ from Qinghua University, she worked as an engineer.

75. They have made a r_____________ for international help.

76. She p_____________ the yellow dress to the red one because it fits her better.

77. He has all the _____________(品质) of a successful businessman.

78. In class, you should be very a_____________ in answering the questions your teacher asks.

79. What is your father’s _____________(态度) towards your plan?

80. Lucy is a r_____________ girl, and you can depend on her.

题型:单项选择题

一个圆柱的底面半径是3分米,高2分米,它的侧面积是______平方分米,表面积是______平方分米,体积是______立方分米.

题型:单项选择题

除去下列各物质中的杂质(括号内为杂质),写出所加试剂(或方法),属离子反应的写出离子方程式.

(1)CO2(HCl)________,__________________________.

(2)KCl(K2CO3)________,________________________.

(3)CO(CO2)________,____________________________.

(4)Cu(CuO)________,____________________________.

题型:单项选择题

肾功能不全的中重度高血压是首选

题型:单项选择题

盐酸去氧肾上腺素

A.火焰反应,火焰显紫色
B.供试品的吡啶溶液加铜吡啶试液1滴,即显紫色
C.供试品溶液加硝酸,即显红色,渐变为黄色
D.制备衍生物测其熔点,应为174~178℃
E.供试品溶液与三氯化铁试液作用,即显紫色
以下药物的鉴别反应为

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