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问题 填空题

宽带无线接入技术主要有本地多点分配业务(LMDS)和 【20】 两种。

答案

参考答案：【20】多通道多点分配业务或MMDS

解析：【解析】宽带无线接入技术主要有本地多点分配业务(LMDS)和多通道多点分配业务(MMDS)两种。它们是在成熟的微波传输技术上发展起来的，不同之处是，MMDS和LMDS均采用一点多址方式，微波传输则采用点对点方式。

选择题

下列各组物质，由金属跟同一种稀酸直接作用生成的是（　　）

A．ZnCl2和ZnSO4

B．ZnSO4和FeSO4

C．FeCl2和FeCl3

D．ZnSO4和CuSO4
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单项选择题

In the United States, older people rarely live with their adult children. But in many other cultures children are expected to care (1) their aged parents. In some parts of Italy, the percentage of adult children who (2) with their parents (3) 65 to 70 percent. In Thailand, too, children are expected to take care of their elderly parents; few Thai elderly live (4) . What explains these differences in living arrangements (5) cultures Modernization theory (6) the extended family household to low levels of economic development. In traditional societies, the elderly live with their children in large extended family units for economic reasons. But with modernization, children move to urban areas, leaving old people (7) in (8) rural areas. Yet modernization theory cannot explain why extended family households were never common in the United States or England, or why families in Italy, which is fully modernized, (9) a p tradition of intergenerational living. Clearly, economic development alone cannot explain (10) living arrangements. Another theory associated intergenerational living arrangements with inheritance patterns. In some cultures, the stem family pattern of inheritance (11) . (12) this system, parents live with a married child, usually the oldest son, who then (13) their property when they die. The stem family system was once common in Japan, but changes in inheritance laws, (14) broader social changes brought (15) by industrialization and urbanization, have (16) the (17) .In 1960 about 80 percent of Japanese over 65 lived with their children; by 1990 only 60 percent did-a figure that is still high (18) U.S. standards, but which has been (19) steadily. In Korea, too, traditional living arrangements are (20) : the percentage of aged Koreans who live with a son declined from 77 percent in 1984 to 50 percent just 10 years later. Although most elderly Koreans still expect to live with a son, their adult children do not expect to live with their children when they grow old.

7（）

A.aside

B.after

C.over

D.behind
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