下列事例中,做功改变物体内能的是( ) A.把水放进电冰箱冷冻室,使水变成冰 B

题型:问答题

问题:

下列事例中,做功改变物体内能的是(  )

A.把水放进电冰箱冷冻室,使水变成冰

B.瓶装牛奶放在热水里,牛奶温度升高

C.夏天,公路路面被晒得很热

D.冬天,两手用力搓,手变得暖和

考点:物体内能的改变方法(做功、热传递)
题型:问答题

如图甲是某电热器的电路示意图.其中R1=R2=60.5Ω

(1)正常情况下,零线和地线之间的电压为_________V.

(2)电热器有高、低温两档,当旋纽开关拨至触点“1”时,该电热器处于_________,此时电热器消耗的电功率为多少?

(3)有金属外壳的用电器,使用的都是三脚插头和三孔插座,目的是_________.如果请你为这台电热器配备一个三脚插头,如图乙所示,应该将电路图中的E接到插头的_________

(4)为了辨别火线和零线,选用测电笔时,正确的方法是图_________(选填“a”或“b”).

(5)当电热器在旋钮开关接触点“0”和“2”时的电功率分别为多少?接触点“2”时通电1min产生的热量是多少?

(6)小明想在电路中加一个“倾倒开关”,使电热器被碰倒时能自动断开电路,以免引起火灾.该开关最好应安装在示意图中A、B、C、D、E中的_________.

题型:问答题

廉洁奉公、不谋私利、尽职尽责,保证药品质量是()

A.药品采购供应的职业道德

B.药品安全储运的道德要求

C.药品生产企业销售的工作道德

D.药品调剂配发的工作道德

E.药品广告宣传的道德责任

题型:问答题

高架绝缘斗臂车在110kV设备上工作,绝缘臂的有效长度应该多长?

题型:问答题

阅读理解。

     The new dollar coin honors Thomas Jefferson, the nation's third president. The nation's first president,

George Washington, was honored with a similar coin in February. A coin honoring second president John

Adams appeared in May. And one honoring fourth president James Madison will follow in November.

      Congress created the program in the Presidential Dollar Coin Act of 2005. it calls for the secretary of

the treasury to design and produce presidential dollar coins honoring each president in the order in which

they served. Four coins will be released each year.

     The coins show the president and his years in office on one side. The other side shows the Statue of

Liberty.

     The presidential coins are the same size and color and have an educational value. They can teach the

American public about past presidents.

     A study carried out last month found that the public does not really know much about the presidents.

Only about thirty percent of Americans could name Thomas Jefferson as the nation's third president.

Ninety-four percent knew that George Washington was the first president. But only seven percent could

name the first four presidents in order.

1. How many presidential coins have been released by now according to Para.1 _____.

A. None

B. Two

C. Three

D. Four

 2. According to the passage, presidential coins _____.

A. are released in the order in which presidents served

B. will be released four coins each year

C. are the same size and color and have an educational value

D. all the above

3. A study showed the following statements EXCEPT ______.

A. only about 30% of Americans could know Thomas Jefferson

B. 94percent knew that George Washington was the first president

C. only seven percent could name the first four presidents in order

D. only about 30% of Americans could name Thomas Jefferson as the nation's third president

4. The presidential coins aims to _____.

A. teach the American public about past presidents

B. release some new coins for the public

C. help collectors of coins

D. show America are rich and developed

题型:问答题

主轴点检项目:主轴外观、主轴与轮毂连接螺栓、()、主轴端盖螺栓、主轴前后轴承加油

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