为了使单摆做简谐运动的周期变长，可以使（ ) A．单摆的振幅适当加大 B．单摆的

“益火之源，以消阴翳”的治法适用于（）。

A.实寒证

B.实热证

C.虚寒证

D.虚热证

E.阴阳两虚证

（12分）实验室可利用乙醇、铜或铜的化合物制备乙醛，下图是某兴趣小组设计的实验装置，右边的反应装置相同，而左边的气体发生装置不同，试管C中装有水(加热装置未画出)。试回答：

（1）在仪器组装完成后，加装试剂前必须要进行的操作是                        ；

（2）两套装置中的A、B处都需加热，A处用水浴加热，B处用             加热，A处用水浴加热的主要优点是                    。

（3）若按甲装置进行实验，B管处装铜粉，则通入A管的X是    ，B中反应的化学方程式为             。

（4）若按乙装置进行实验，则B管中应装          ，

B中反应的化学方程式为                                  。

（5）实验结束后，将C试管中的溶液滴入新制的氢氧化铜溶液中并加热，可观察到的

现象        ，写出该过程的化学方程式                               。

A characteristic of American culture that has become almost a tradition is to respect the self-made man—the man who has risen to the top through his own efforts, usually beginning by working with his hands. While the leader in business or industry or the college professor occupies a higher social position and commands greater respect in the community than the common laborer or even the skilled factory worker, he may take pains to point out that his father started life in America as a farmer or laborer of some sort.

This attitude toward manual labor is now still seen in many aspects of American life. One is invited to dinner at a home that is not only comfortably but even luxuriously furnished and in which there is every evidence of the fact that the family has been able to afford foreign travel, expensive hobbies, and college education for the children; yet the hostess probably will cook the dinner herself, will serve it herself and will wash dishes afterward, furthermore the dinner will not consist merely of something quickly and easily assembled from contents of various cans and a cake or a pie bought at the nearby bakery. On the contrary, the hostess usually takes pride in careful preparation of special dishes. A professional man may talk about washing the car, digging in his flowerbeds, painting the house. His wife may even help with these things, just as he often helps her with the dishwashing. The son who is away at college may wait on table and wash dishes for his living, or during the summer he may work with a construction gang on a highway in order to pay for his education.

Which of the following may serve as the best title of the passage（）

A. A Respectable Self-made Family

B. American Attitude toward Manual Labor

C. Characteristics of American Culture

D. The Development of Manual Labor

发电机跳闸的处理步骤是什么？