生产经营单位的主要负责人对本单位安全生产工作负什么职责？

刘阳同学想利用下图所给实验器材，探究电流与电压和电阻的关系。

（1）在电压表尚未接入电路之前，已存在两处明显的连接错误，请你指出：

        ①______________________________                   ； 

       ②_________________________________________。　　

（2）假如错误已纠正，且原电流方向不变，请在图中用笔划线表示导线，将电压表接入R₁两端。 　　

（3）在本实验中，若探究电流与电压的关系，应控制__________不变，这种研究问题的方法叫做__________________。　　

（4）下表是刘阳同学探究电流与电压的关系时记录的几组实验数据，通过对表中数据的分析，可得到的初步结论是：___________________________________。

（5）本实验操作完成后，如果将电阻R₁改接成一只小灯泡，还可以测出小灯泡的_______或______。

钙拮抗剂（）

A．青霉素V 

B．苯唑西林 

C．替卡西林 

D．哌拉西林 

E．舒巴坦

男性，28岁，左腰背酸胀5个月，CT检查如图所示，应诊断为()

A．左肾上腺髓样脂肪瘤

B．左肾上腺错构瘤

C．左肾上腺嗜铬细胞瘤

D．左肾上腺腺瘤

E．左肾上腺转移瘤

鲁迅1921年12月发表的中篇小说（），是中国现代文学史上的不朽杰作。

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.

（18）是（）

A.by

B.on

C.with

D.in