Topic sentence ___________

　　At one time, transistor radios were not practical, because they were too expensive, Now all of that has changed. With the reduced price of transistors and the cheaper costs of mass production, the transistor radio is cheaper than the old-style tube model. In addition, transistor radios do not heat up like the old tube radios, so they will not wear out as quickly. Also, transistor radios can be made much smaller because transistors are smaller than tubes. Furthermore, transistor radios are more reliable. They have fewer parts, so less can go wrong.

　　A. Transistor radios are practical and inexpensive.

　　B. Transistor radios have undergone much improvement.

　　C. Transistor radios are cheaper than tube radios because of mass production.

　　D. Transistor radios are better than the old-style tube radios.

　　Ⅳ. 重新组合段落(10 points, 2 points each)

　　Rearrange the following numbered sentences so that they will read logically, put the number in proper sequence in the boxes provided below.

　　19. Those who did not become miners found work in railroad construction, farming and light industries, doing low-paid jobs.

　　20.As in California they formed small pockets of Chinese culture that were known as "Chinatowns".

　　21. The government issued Exclusion Acts to stop the immigration of Chinese laborers into the  United States.

　　22. The Chinese called the new land "Mountain of Gold".

　　23. Many workers fled the concentrated Chinese communities in the West and scattered to the Mid-west and the East.

　　24. He was accused of taking jobs away from the white man.

　　25. By the 1880's, American industrialization brought changing economic realities, resulting in an explosion of resentment toward the Chinese laborer.

　　26. The first big wave of Chinese immigration to America came when gold was discovered in California in 1848.