某中学初三年级A、B两个班同学分别做常见酸和碱与指示剂反应的实验,使用的试剂如下

题型:问答题

问题:

某中学初三年级A、B两个班同学分别做常见酸和碱与指示剂反应的实验,使用的试剂如下图所示.实验后废液分别集中到各班的一个指定废液缸中.研究小组对两个班的废液进行检测,结果如下表.

废液来源检测方法与结果推测废液成分(填物质化学式,酚酞和水不填)
A班观察废液呈红色废液中含有______
B班观察废液呈无色,测pH=2废液中没有______,含有______

考点:溶液的酸碱性与pH值酸碱指示剂中和反应及在实际中的应用离子的共存
题型:问答题

如图所示,欲使用一平面镜将与水平面夹角为30o的入射光线沿水平方向射出,请你用作图的方法确定平面镜的位置(保留作图痕迹)。

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亲水性大于苯,能与水混溶的是()

A.苯

B.氯仿

C.乙醚

D.丙酮

E.乙酸乙酯

题型:问答题

大帝房地产公司依法以出让的方式取得某块土地的使用权,进行房地产开发活动,在开发过程中,大帝公司决定进行商品房预售,那么依照我国法律规定,其进行应当满足以下哪些条件

A.已交付全部土地使用权出让金,取得土地使用权证书

B.持有建设工程规划许可证

C.按提供预售的商品房计算,投入开发建设的资金达到工程建设总投资的白分之三十以土,并已经确定施工进度和竣工交付日期

D.向市级以上人民政府房产管理部门办理预售登记,取得商品房预售许可证明

题型:问答题

Passage Three

Believe it or not,optical illusion can cut highway crashes.

Japan is a case in point.It has reduced automobile crashes on some roads by Rearly 75 percent using a simple optical illusion.Butst.ripes,called chevrons(人字形),painted on ther rads make drivers think that they are driving faster than they really are,and thus drivers slow down.

Now the American Automobile Association Foundation for Traffic Safety in Washington D.C. is planning t。repeat Japan’s success.Starting next year,the foundati。n will paint cheyrons and。ther pattems of stripes on selected roads around the country to test how well the patterns reduce highway erashes.

Excessive(too great)speed plays a major role in as much as one fifth of all fatal traffic accidents, according to the foundation.To help reduce those accidents,the foundation will conduct its tests in areas where speed-related hazards(danger)are the greatest curves,exit slopes,traffic circles,and bridges.

Some studies suggest that straight,horizontal bars painted across roads can initially cut the average speed of drivers in half.However,traffic。ften returns to full speed within months as driVers become used to seeing the painted bars.

Chevrons,scientists say,not only give drivers the impression that they are driving faster than they reallv are but als0 make a lane appear to be narrower.The result is a longer lasting reduction in highway speed and the number of traffic accidents.

On roads painted with chevrons,drivers tend to feel that().

A.thev should avoid speed.related hazards

B. they are driving in the wrong lane

C. they should slow down their speed

D. they are coming near to the speed limit

题型:问答题

正投影法的基本性质说法错误的是()。

A.直线的投影为直线

B.平面垂直于投影面,投影积聚成直线

C.直线平行于投影面,投影体现实际长度

D.平面倾斜于投影面,投影形变小

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