下列做法能达到实验目的的是 A.粗略地测定空气中氧气的含量:用铁丝代替红磷 B.

题型:选择题

问题:

下列做法能达到实验目的的是

A.粗略地测定空气中氧气的含量:用铁丝代替红磷

B.除去CO2中少量的CO:将气体通入足量澄清的石灰水

C.鉴别真黄金和假黄金(铜锌合金):将稀硫酸滴在金属表面

D.证明二氧化碳的密度比空气大:用烧杯罩住一支燃着的蜡烛

考点:水(蒸气)的检验粗盐的提纯空气的检验物质的相互转化和制备
题型:选择题

语法填空。

     The most common problem that worries all of us today is the fear of insecurity. Life has become so

competitive that every now and then we are struck by the fear of the _1_ (know).   2   every new turn

of events our selfconfidence takes a blow. The  3   (big) challenge before every person today is not to

lose confidence in one's ability.

     There are several reasons that affect a person's selfconfidence. The most important reason is lack

of success. Not being able to    4   (success) affects one's selfconfidence greatly. This is   5   one begins

to doubt his own ability. In many cases one's selfconfidence is low when he feels rejected by society.

For example, a person who loses his job keeps away from other people for fear of    6   (question)

about his work. However, this isn't right. One needs to think along positive lines in spite of failures.

     The challenge lies in not allowing your selfconfidence to decrease.    7   lack of success causes you

to doubt your ability, don't forget to remind yourself that quick success does not last long. Also

remember not to compare yourself with others. These tips will do   8   world of good to your confidence.

In order to be selfconfident, you need to have a lifestyle that is right for you. Create one and live a life

   9   you want to. Leave others to 10  .

题型:选择题

对于诊断肺炎球菌性肺炎,下列症状中价值最大的是()。

A.寒战

B.持续高热

C.咳嗽、呼吸困难

D.咯铁锈色痰

E.胸痛

题型:选择题

在船舶吃水一定的情况下,船舶基本阻力随船速的增大而增加,且:()

A.在低速时基本呈线性关系,高速时呈非线性关系

B.在低速时呈非线性关系,高速时基本呈线性关系

C.在低速和高速时都基本呈非线性关系

D.在低速和高速时都基本呈线性关系

题型:选择题

根据《中华人民共和国土地管理法》规定,通过编制土地利用总体规划,规定土地用途,下列选项中,不属于建设用地的是( )。

A.旅游用地
B.军事设施用地
C.农田水利用地
D.交通水利设施用地

题型:选择题

第一角和第三角画法的主要区别不包含()

A.各视图的配置位置不同

B.里后外前

C.里前外后

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