造成乙炔瓶充装量失常的原因有那些？

《高层民用建筑设计防火规范》规定，高层建筑内消防用电设备的配电线路当采用阻燃或耐火电缆时，敷设在（）内可不采取防火保护措施

A.金属管

B.封闭的金属线槽

C.电缆井

D.电缆沟

寡头垄断型市场是指相对少量的生产者在某种产品的生产中占据很大市场份额，从而控制了这个行业的供给的市场结构，该市场结构得以形成的原因有（）。

A.由于产品差异性的存在，生产者可以树立自己产品的信誉，从而对其产品的价格有一定的控制能力

B.这类产品通常因获得政府授予的特许专营而阻碍了其他生产者进入

C.这类行业初始投入资本较大，阻止了大量中小企业的进入

D.这类产品只有在大规模生产时才能获得好的效益，这就会在竞争中自然淘汰大量的中小企业

（）是美国最早的建筑流派，是现代建筑在美国的奠基者。

A.新泽西派

B.华盛顿派

C.波士顿派

D.芝加哥学派

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.

（3）是（）

A.amasses

B.amounts

C.attains

D.reaches

女孩，7岁。因逐渐加重的多发性关节肿痛被诊断为儿童类风湿病。检查：双侧膝、肘关节对称性、游走性肿、痛、热，活动受限，特点为晨僵。全身无其他明显不适。该患儿与风湿热关节受累患儿，最明显的区别是______

A．游走性大
B．红肿热痛
C．关节受损
D．关节畸形
E．功能障碍