锻造吊钩一般经（）、热处理和机加工而成。

用1～8这八个数字，按要求组成下列各数（每个数位上的数字都不同）。

（1）十万位上是4，千位上是2的最大八位数是（    ）；

（2）万位上是5的最小八位数是（    ）

阅读理解。

     You may think that sailing is a difficult sport, but it is really not hard to learn it. You do not need to be

strong. But you need to be quick. And you need to understand a few basic rules about the wind.

     First, you must ask yourself, "Where is the wind coming from? Is it coming from ahead or behind or

from the side?" You must think about this all the time on the boat. The wind direction tells you what to do with the sail.

     Let's start with the wind blowing from the behind. This means the wind and the boat are going in the

same direction. Then you must always keep the sail outside the boat. It should be at a 90° angle (角度)

to the boat. Then it will catch the wind best.

     If the wind is blowing from the side, it is blowing across the boat. In this case, you must keep the sail

half way outside the boat. It should be at a 45 ° angle to the boat. It needs to be out far enough to catch

the wind, but it shouldn't flap (摆动). It shouldn't look like on a flagpole. If it is flapping, it is probably out

too far, and the boat will slow down.

     Sailing into the wind is not possible. If you try, the sail will flap and the boat will stop. You may want

to go in that direction. It is possible, but you can't go in a straight line. You must go first in one direction

and then in another. This is called tacking. When you are tacking, you must always keep the sail inside

the boat.

1. What should you consider first while sailing?

A. Sailors' strength.

B. Wave levels.

C. Wind directions.

D. Size of sails.

2. What does the word "It" underlined in Paragraph 4 refer to?

A. The boat.

B. The wind.

C. The sail.

D. The angle.

3. What do you have to do when sailing against the wind?

A. Move in a straight line.

B. Allow the sail to flap.

C. Lower the sail.

D. Tack the boat.

4. Where can you probably find the text?

A. In a popular magazine.

B. In a tourist guidebook.

C. In a physics textbook.

D. In an official report.

长期服用下列药物会造成牙齿酸蚀症，除了（）。

A.补铁药

B.口嚼型维生素C

C.口嚼型阿司匹林

D.口嚼型钙片

E.用于胃酸缺乏症的替代性盐酸

价格对社会供求有着很大的反作用，价格等于价值时，表现为（）。

A.供大于求

B.供求平衡

C.供小于求

D.价格=价值