如图所示,当开关S由闭合变为断开时,下列说法中不正确的是 [ ] A.电路中的电

题型:选择题

问题:

如图所示,当开关S由闭合变为断开时,下列说法中不正确的是

[ ]

A.电路中的电流为零

B.灯泡两端电压为零

C.电灯的电阻为零

D.电源两端的电压不为零

考点:电压的测量,电压表的使用
题型:选择题

下列哪类细胞不表达MHCⅡ类分子()

A.活化的Th细胞

B.Mφ

C.B淋巴细胞

D.树突状细胞

E.胰岛β细胞

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下面有关藻酸盐印模材料组成成分的说法,错误的是()

A.缓凝剂的作用是减缓藻酸盐溶胶与胶结剂硫酸钙的反应速度

B.缓凝剂的作用具有加速藻酸盐配制时的溶解作用

C.滑石粉、硅藻土等填料成分在印模材料中的作用是增加藻酸盐凝胶的强度

D.填料粒子越大,取制的印模精确度越高

E.硼砂、硅酸盐等增稠剂的作用是增加溶胶的稠度,提高材料韧性,调节印模材料的流动性,并且有一定加速凝固作用

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放在水平地面上的砖,若沿如图所示中的虚线截为相同两块后,再平叠在一起,则前后两次

[ ]

A、对地面的压强之比为1∶2

B、对地面的压强之比为1∶1

C、密度之比为2∶1

D、受地面的支持力为1∶2

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Low levels of literacy and numeracy have a damaging impact on almost every aspect of adults, according to a survey published yesterday, which offers (1) of a developing underclass. Tests and (2) with hundreds of people born in a week in 1958 graphically illustrated the (3) of educational underachievement. The effects can be seen in unemployment, family (4) , low incomes, depression and social inactivity.

Those who left school at 16 with poor basic skills had been employed for up to four years less than good readers (5) they reached 37. Professor John Bynner, of City University, who carried the research, said that today’s (6) teenagers would even encounter greater problems because the supply of (7) jobs had shrunk.

Almost one fifth of the 1,700 people interviewed for yesterday’s report had poor literacy and almost half (8) with innumeracy, a proportion (9) other surveys for the Basic Skills Agency. Some could not read a child’s book, and most found difficult (10) written instruction.

Poor readers were twice as likely to be a low wage and four times likely to live in a household where partners worked. Women in this (11) were five times as likely to be (12) depressed, (13) both tended to feel they had no control over their lives, and to trust others (14) .

Those who had low literacy and numeracy were seldom (15) in any community organization and less likely than others to (16) in a general election. There had been no (17) in the literary level of (18) reporting problems.

Alan Wells, the agency’s director, said: “ The results emphasize the dangers of developing an underclass people, who were out of work, (19) depressed and often labeled themselves as (20) . There is a circle of marginalization, with the dice against these people and their families.”

19()

A.hardly

B.seriously

C.increasingly

D.potentially

题型:选择题

建筑物沉降观测时,在一个观测区,水准点不少于()个。

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