雷电是自然界中的一种()现象。A、导电  B、放光  C、放巨响  D、放电

题型:单项选择题

问题:

雷电是自然界中的一种()现象。

A、导电 

B、放光 

C、放巨响 

D、放电

考点:低压电工考试低压电工考试题库
题型:单项选择题
设定义域为r的函数f(x)=
|lgx|        x>0
-x2-2x      x≤0
,若关于x的函数y=2f2(x)+2bf(x)+1有8个不同的零点,则实数b的取值范围是(  )
A.-
3
2
<b
2
B.-
3
2
<b<-
2
C.-2<b<-
2
D.-
3
2
<b<-
2
或b
2
题型:单项选择题

关于桑椹胚和囊胚的比较,以下说法正确的是[ ]

A.囊胚期细胞分化是由于遗传物质突变引起的

B.原肠胚期的细胞开始出现了细胞分化, 但遗传物质未发生改变

C.桑椹胚的各细胞结构功能基本相同

D.囊胚期内细胞团和滋养层细胞差异不是复制水平上的差异,而是转录水平上的差异引起的

题型:单项选择题

患者,女,60岁。素有高血压病史,卒然昏厥,不省人事,两手握紧,牙关紧闭,右侧肢体偏瘫。首选药物是()

A.冰片

B.麝香

C.石菖蒲

D.郁金

E.苏合香

题型:单项选择题

影响遗传力大小的因子的原因有哪些?

题型: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.

4()

A.lone

B.alone

C.lonesome

D.lonely

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