问题 填空题

商场里的保洁员在拖过地后,常用电风扇对着地面吹,这样做的目的是通过加快空气流动来加快     (填物态变化的名称),使地面尽快变干。

答案

汽化或蒸发。

拖过地后地面的水变成水蒸气蒸发到空气中,有液态到气态为汽化。汽化两种方式蒸发和沸腾。影响蒸发的因素有三种:温度,表面积和表面空气流动速度。

阅读理解

阅读理解。

     Hiking is not only one of the best forms of physical exercise, but it is also one of the best forms of mental

relaxation. It is good for all ages and especially good as a family and group activity.

     Since there are so many different kinds of hiking, it is not possible to give any general rules to follow. Short

and frequent hikes, needing no planning or special equipment, are enjoyed by most people.

     * Keep in shape by walking at a fast pace for at least 15 minutes every day. Climbing stairs instead of using

a lift and running not too far is also a good way of keeping in shape.

     * On any hike nothing is more important than good, comfortable shoes.

     * The things you take might include matches in a waterproof box, a knife, compass, map, first aid items and

flashlight.

     * Cameras may be taken, but don't load with too much.

     * On longer hikes keep a comfortable, steady pace and take rest stops often.

     * Drink only safe water. If in doubt, boil the water.

     * Don't go along the busy roads. When you have to use a road, keep as far over on the left as possible.

     * Leave word at home or some other places as to where you are going and when you plan to return.

     * On almost any hike, a map is a good idea. If going into a strange place, a detailed map is most helpful.

     * Take along a field guide on flowers, birds, rocks, or other subjects depending upon your interests. This

can add greatly to the enjoyment and educational value of your hike.

1. The author feels that the most essential thing on a hike is ____.

A. a new map

B. a set of outdoor tools

C. a pair of good shoes

D. only safe water

2. The author thinks that hiking is especially valuable for ____.

A. single persons

B. families

C. old people

D. everyone

3. Generally speaking, hiking is ____.

A. a relaxing form of exercise

B. a dangerous activity for older people

C. not as popular as it was once

D. a good way of keeping in shape

4. The author mostly talks about ____.

A. general rules for hiking in mountainous areas

B. steps to be taken against dangerous animals

C. general things that should be paid attention to in hiking

D. all the things that are needed in hiking

5. The author suggests ____.

A. leaving cameras at home

B. drinking water from streams only

C. carrying more clothes

D. keeping away from heavy traffic

单项选择题