试题与答案

如图,人重600牛,平板重400牛,如果人要拉住木板,他必须用多大的力(滑轮重量

题型:计算题

题目:

如图,人重600牛,平板重400牛,如果人要拉住木板,他必须用多大的力(滑轮重量和摩擦均不计)?

答案:

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参考答案:C解析:本组题考查各药物的临床应用和作用特点。硝苯地平通过阻滞钙通道,抑制细胞钙内流,降低心肌收缩力,进而降低心肌耗氧量而产生抗心绞痛作用,临床用于变异性心绞痛的治疗;普萘洛尔通过阻断β受...

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题型:阅读理解

More than 6000 children were expelled(开除)from US schools last year for bringng guns and bombs to school,the US Department of Education said on May 8.

The department gave a report on the expulsions(开除)as saying handguns accounted for 58 per cent of the 6093 expulsions in 1996—97,against 7 per cent for rifles or shotguns and 35 per cent for other types of firearms.

“The report is a clear sign that our nation’s public schools are cracking down(严惩)” on students who bring guns to school,“Education Secretary Richard Riey said in a statement.“We need to be tough-minded(坚强的)about keeping guns out of our schools and do everything to keep our children safe.”

In March 1997,an 11-year-old boy and a 13-year-old using hand-guns and rifles shot dead four children and a teacher at a school in Jonesboro,Arkansas.In October,two were killed and seven wounded in a shooting at a Mississippi school.Two months later,a 14-year-old boy killed three high school students and wounded five in Daducab,Kentucky.

“Most of the expulsions,56 per cent,were from high schools,which have students from about age 13,34 per cent were from junior high schools and 9 per cent were from elementary schools.” The report said.

小题1:From the first paragraph we can see that in the US schools ____________.

A.students enjoy shooting

B.students are eager to be soldiers

C.safety is a problem

D.students can make guns小题2:The report from the US Department of Education shows that _____________.

A.the number of the expulsions is now large

B.the number of the expulsions is wrong

C.there are soldiers hiding among the students

D.guns are out of control in US schools小题3:The main idea of paragraph four shows us _____________.

A.some examples of shootings in US schools

B.the Americans’ feeling

C.some famous schools

D.that some teachers were killed by students小题4:How many students were shot dead in 1997 in US schools?

A.10

B.9

C.12

D.22小题5:From this passage we know that ____________.

A.every American cannot have guns

B.only soldiers and police can have guns

C.American citizens can own guns

D.teachers have no money to buy guns

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