线形痕迹不仅与工具接触面有关，而且与工具的（），力的大小密切相关。A、接触面的方向

发布时间：2017-10-23 13:33 │ 来源：www.tikuol.com

题型：单项选择题

问题：

线形痕迹不仅与工具接触面有关，而且与工具的（），力的大小密切相关。

A、接触面的方向

B、接触面的角度

C、力的大小

D、力的方向

考点：经济犯罪侦查执法资格考试经济犯罪侦查执法资格考试题库

题型：单项选择题

完形填空。
Jennifer was sitting on the beach. After all she had been through, it was just what she needed. It’s getting __1__,“ she thought. “I should go home.” She wanted to know how her __2__ would react, when she __3__ home after the three days she was missing. It was really dark when she finally reached her front door. It seemed different to her. __4__ had taken care of the outside garden for __5__ days. She was surprised as her father usually worked hard to keep everything __6__ and tidy. She couldn’t understand what was going on. She entered the __7__. First, she went into the kitchen __8__ she saw a note written by her father. __9__said, “Dear Ellen, here is some coffee. I am out searching*.” Ellen was her mother, but where was she? She went to her parents’ room. She found her there. Her __10__ was lying on the bed, fast sleep. Her face looked so __11__, as if she hadn’t slept for days. Jennifer wanted to wake her up __12__ she looked too tired. So Jennifer just fell asleep beside her. When Jennifer __13__, something was different: she wasn’t in her mother’s room anymore and she wasn’t wearing the old clothes she ran away __14__. She was on her own bed. It felt so good being back home. Suddenly she heard a voice ask, “Are you feeling better now, dear? You know you __15__ us all very, very scared.”
( )1. A. early ( )2.A. father ( )3.A. got ( )4.A. Everybody ( )5.A. many ( )6.A. clean ( )7.A. school ( )8.A. what ( )9.A. They ( )10.A. mother ( )11. A. happy ( )12.A. and ( )13.A. got up ( )14.A. out ( )15.A. had	B. late B. mother B. left B. Somebody B. lots of B. dirty B. room B. when B. It B. father B. tired B. so B. woke up B. on B. let	C. warm C. parents C. wanted C. Anybody C. a few C. quiet C. house C. who C. He C. friend C. scared C. but C. put up C. of C. made	D. angry D. teachers D. missed D. Nobody D. much D. busy D. library D. where D. She D. sister D. relaxed D. although D. clean up D. in D. gave

查看答案

题型：单项选择题

草酸的化学式为H₂C₂O₄，甲、乙两同学对草酸受热分解及其产物的检验做了探究：（1）猜想与假设

第一种：草酸分解产物是CO₂和H₂；第二种：草酸分解产物是CO₂、CO和H₂O；

第三种：草酸分解产物是CO₂和H₂O；第四种：草酸分解产物是CO₂、CO．

以上猜想，第______种一定不可能，原因是______．

（2）查阅资料无水硫酸铜遇水由白色变成蓝色，碱石灰是一种常用的干燥剂．

（3）实验设计（图中铁架台略去）甲同学设计了甲装置，乙同学设计了乙装置．

（4实验过程甲同学按甲装置实验，在给草酸晶体加热时，先______，然后固定在______底部加热，过一会儿观察到澄清石灰水变浑浊；乙同学按乙装置实验，观察到无水硫酸铜由白色变成蓝色，澄清的石灰水变浑浊，且生成的气体通过碱石灰后，在干燥管的尖嘴处点火能燃烧，乙同学进一步通过实验验证燃烧的气体为CO，他的操作是______，现象是______．

（5）实验结论第______种猜想是正确的，请写出草酸受热分解的化学方程式______．

（6）反思与评价乙同学认为甲同学设计的实验装置有缺陷．由于试管口向下倾斜，而且草酸晶体熔点较低，加热到182℃便开始熔化，因此实验中常会出现熔融的草酸流进导管而影响后续实验．甲同学认为乙同学的设计是科学合理的．请你谈谈乙装置优于甲装置之处______．（答出一点即可）

查看答案

题型：单项选择题

成组设计的方差分析中，必然有（）

A.A

B.B

C.C

D.D

E.E

查看答案

题型：单项选择题

对装饰材料的质量要求，除满足功能需要外，为了保证其装饰效果，还注意（）方面。

A、材料的颜色、光泽、透明度

B、材料的表面组织

C、材料的形状尺寸

D、以上全部

查看答案

题型：单项选择题

“钉眼”是位于衣片内部的标记，钉眼的位置一般要比标置位置缩进（）。

A.0.3cm

B.0.4cm

C.不用缩进

D.0.5cm

查看答案

更多题库