问题

学习完第二次世界大战的历史后,小刚同学整理出以下知识点,你认为正确的是

①德国、意大利、日本是第二次世界大战的罪魁祸首 

②斯大林格勒战役是第二次世界大战的重要转折点

③雅尔塔会议决定战后成立联合国

④第二次世界大战是正义的反法西斯战争

A.②③④

B.①②③

C.①②③④

D.①③④

答案

答案:C

题目分析:本题考察学生对二战的认识,根据所学知识,二战的轴心国是德日意,它们是二战的罪魁祸首,①正确,苏德战场是欧洲反法西斯的主战场,斯大林格勒战役的胜利成为二战的转折点,②正确,战争期间召开了雅尔塔会议,决定战后成立联合国,③正确,二战的性质是世界反法西斯战争,④正确,因此①②③④都对,本题选C。

点评:本题难度较小,考察学生对历史知识的识记能力,两次世界大战给我们的教训是和平来之不易,我们要倍加珍惜,战后世界格局的变化是我们认识到,发展经济,增强国力是我们的首要目标,我们要坚持改革开放,为把我国变成一个文明富强的国家而奋斗。

选择题
阅读理解

Today, ultrasonic(超声的) waves are being put to work in laboratories and factories. If an ultrasound generator is placed in a liquid, the waves move the liquid back and forth hundreds of thousands of times each second. This causes materials to mix quickly or to dissolve(使分解,使溶解) in liquids. Paint manufacturers(制造商) use ultrasound to do a better job of blending colors. The companies that make film for your camera find that mixing chemicals by the use of sound waves will produce a more sensitive film.

The new lightweight(轻量的) type of washing machine uses ultrasonic waves to get clothes clean. Its special ultrasound generator is put into a pail of soapy water containing the soiled clothes. The sound waves drive the soapy water back and forth through the cloth so fast that everything is soon clean. There is also a new kind of dishwasher that works in much the same way.

Ultrasonic waves can shake a liquid so fast that tiny holes form all through it. The liquid is actually torn apart by this action. Almost as soon as these holes are made, they fall together again. The result is a powerful pounding action. In the dairy industry this is used for the double purpose of making homogenized(使均匀,使匀质) milk and sterilizing(使无菌) it at the same time. If you look at some raw milk with a microscope, you find that it is made up of little drops of butter fat floating around in a watery liquid. In order to make milk easier to digest, these fat droplets(微粒) may be broken up by forcing the milk through very small openings. The result is called homogenized milk. When the ultrasonic method is used, the sound waves not only break up the droplets but also kill the germs in the milk by pounding them to pieces. (from www.nmet168.com)

1. Why does a paint manufacturer use ultrasound to do a better job of blending colors?

A. Because it is cheap to use ultrasound to blend colors.

B. Because the waves move the liquid so quickly that it can make materials mix quickly or dissolve in liquids.

C. Because they can mix chemicals by the use of sound waves.

D. Because the waves can clean the paint.

2. What properties does ultrasound wave have?

A. Homogenizes and sterilizes the milk.   B. Mix materials and break droplets.

C. Kill germs and sterilize milk.          D. Move liquids quickly.

3. What exists in the raw milk?

A. Little drops of butter fat.       B. Small holes.

C. Fat droplets and germs.        D. Chemicals.

4. Where is ultrasound wave not used?

A. In the paint manufacture.                  B. In the shop mixing bread flour.

C. In the film-making company.      D. In the dairy industry.