1,2-二溴乙烷(ISO)

在（）以后，视敏度和视觉感受性逐渐下降。

A.30岁

B.40岁

C.50岁

D.60岁

测量电容比时，最有效的方法是用测量电容比法来检验纤维绝缘的（）。

A．感应状态

B．饱和状态

C．工作状态

D．受潮状态

直流电路欧姆定律是说什么？

阅读材料，回答问题。材料一：国民经济问题可以简单理解为总供给和总需求的平衡。以往靠投资、消费和出口“三驾马车”拉动需求带动经济发展的方式属于需求侧管理。目前，中国的供给体系无法更好适应需求结构的变化，如：中国生产的电饭煲、马桶盖等相关产品产量较大，但中国人却不吝重金到海外购买日本品牌。在需求倒逼的压力之下，“供给侧改革”势在必行。材料二：2015年11月10日，习 * * 同志在中央工作会议中强调：在适度扩大总需求的同时，着力加强供给侧结构性改革，着力提高供给体系质量和效率，增强经济持续增长动力，推动我国社会生产力水平实现整体跃升。供给侧改革，将有利于增强企业创新能力、提高供给质量与效率、改善供给结构。

结合材料，运用唯物辩证法实质与核心的知识，分析宏观调控从单纯的需求刺激，到需求和供给“双轮驱动”的哲学依据。

If you left your book on the table overnight, you would find the following morning that it was still exactly where you had left it, provided nobody had moved it. If a ball is made to roll on a very smooth surface, it will roll a long distance unless something stops it or changes its direction. This tendency of an object to remain at rest unless something moves it and to continue moving unless something stops it is known as the Law of Inertia.

The following examples show the truth of this law.

a. Put a table-cloth on a table and arrange a pile of books on it. Hold one edge of the table-cloth and pull it quickly. The table-cloth will come off, leaving the pile of books undisturbed.

b. Place a small piece of cardboard on an open jar and place a coin on it directly over its mouth. Use one finger to flick the piece of cardboard away. You will notice that the coin drops into the jar.

c. Sitting in a car which starts suddenly, you feel you are jerked backwards. In fact, you are not jerked backwards. Your lower half, which is in contact with the cushion, is forced to move forward with the car, and the upper part of your body, which remained at rest, is left behind.

In the first example, the pile of books on the table-cloth will ()

A. be broken into pieces

B. scatter onto the ground

C. remain in its position of rest

D. be wrapped in the table-cloth