将“这种情况与一架天平的来回摆动很相像,所以称为‘天平动’或‘枰动’”这句话还原

题型:选择题

问题:

将“这种情况与一架天平的来回摆动很相像,所以称为‘天平动’或‘枰动’”这句话还原到下面语段中,最恰当的一处是

为此,奥尼尔提出两个地点。

A.它们位于月球环绕地球运行的轨道上,一个在月球前,另一个在月球后,每个点都可以与地球、月球组成一个等边三角形,其边长等于月地之间的距离,即 384400千米。

B.早在1772年,法国天文学家拉格朗日就己证明,位于这两个点上的小物体所受的地球引力和月球引力恰能使之处于稳定平衡状态。

C.也就是说,如果小物体位置稍有偏离,那么地球与月球的引力联合起来又会把它拉回到这两个点上,于是,该小物体就会在平衡位置附近往返摆动。

D.太空中的这两个点则称为“秤动点”或“拉格朗日点”。

考点:仿写句子
题型:选择题

急性前壁心肌梗死,以下各种冠状动脉病变最常见于

A.左冠状动脉前降支

B.左冠状动脉回旋支

C.右冠状动脉

D.左冠状动脉主干

E.左冠状动脉回旋支和右冠状动脉

题型:选择题

阅读理解。

     "It hurts me more than you", and "This is for your own good" -these are the statements my mother

used to make years ago when I had to learn Latin, clean my room, stay home and do homework.

     That was before we entered the permissive period in education in which we decided it was all right

not to push our children to achieve their best in school. The schools and the educators made it easy for

us. They taught that it was all right to be parents who take a let-alone policy. We stopped making our

children do homework. We gave them calculators, turned on the television, left the teaching to the

teachers and went on vacation.

     Now teachers, faced with children who have been developing at their own pace for the past 15 years,

are realizing we've made a terrible mistake. One such teacher is Sharon Clomps who says of her

 students-"so passive" -and wonders what has happened. Nothing is demanded of them, she believes.

Television, says Clomps, contributes to children's passivity. "We're talking about a generation of kids

who' vet never been hurt or hungry. They have learned somebody will always do it for them, instead of

saying 'go and look it up', you tell them the answer. It takes greater energy to say no to a kid."

     Yes, it does. It takes energy and it takes work. It's time for parents to end their vacation and come

back to work. It' s time to take the car away, to turn the TV off, to tell them it hurts you more than them

but it' s for their own good. It's s time to start telling them no again.

1. Children are becoming more inactive in study because _______.

A. they watch TV too often            

B. they have done too much homework

C. they have to fulfill too many duties

D. teachers are too strict with them

2. We learn from the passage that the author's mother used to lay emphasis on _______.

A. learning Latin          

B. discipline

C. natural development  

D. education at school

3. By "permissive period in education" (L.1, Para.2) the author means a time _______.

A. when children are allowed to do what they wish to

B. when everything can be taught at school

C. when every child can be educated

D. when children are permitted to receive education

4. The main idea of the passage is that _______.

A. parents should leave their children alone

B. kids should have more activities at school

C. it's time to be more strict with our kids

D. parents should always set a good example to their kids

题型:选择题

竣工文件应符合下列要求()。

A.内容齐全

B.详实准确

C.清楚规范

D.版面整洁

题型:选择题

用于压铸生产的合金应具有哪些性能?

题型:选择题

目前()是水基压裂液系统的主要稠化剂,占使用量的90%以上。

A.生物聚合物

B.合成聚合物

C.植物胶及其衍生物

D.纤维素衍生物

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