Question

阅读理解 　　Microwave cooking is probably the best cooking discovery besides fire．In fact, it might be better than fire, since microwaves, instead of a flame or an electric element, cook the food． 　　Microwaves are short radio waves, similar to heat and light waves．They work by movement．They cause the molecules(分子)in food to move, which produces friction(摩擦力)．(It’s similar to rubbing your hands together when they’re cold．)The friction produces heat in the food(not in the oven), and the heat cooks the food． 　　There is a legend behind the use of microwaves for cooking． 　　Percy Le Spencer was employed by the Raytheon Company during the World War Ⅱ．One day on 1942 he was working with magnetrons(电磁管), which can produce microwaves．When he pulled a candy bar from his pocket, it was a melted mess．Although Spencer was working on scientific experiments, not trying to invent a new way of cooking, he realized that it was the microwaves that had melted the candy．Spencer knew that if microwaves melted candy, they would cook other foods as well．The Raytheon Company agreed, and in 1947 it introduced its Radarange to the public． 　　The first ovens were suspected(怀疑)of causing health problems, but the new models were safe when the factory’s instructions were followed．Microwave cooking now can be found in many homes all over the world． (1) Microwaves cook food by ________． [　　] A． producing fire B． producing electricity C． giving off heat D． causing the molecules to move (2) Microwave cooking is a great invention made ________． [　　] A． after countless experiments B． by chance C． by the Raytheon Company in 1942 D． by Spencer in 1947 (3) According to the passage, which is TRUE about how microwaves cook food? [　　] A． Microwaves can produce heat to cook the food． B． Microwaves cause food to move so as to produce heat to cook it． C． Microwaves rub the food so as to produce heat to cook it． D． Microwaves cause molecules in food to move, which produces friction that produces heat in food to cook it． (4) What does this passage mainly talk about? [　　] A． An invention discovered by mistake． B． Microwave cooking． C． How microwaves cook food． D． The invention of the first microwave oven．

Answer 1

答案：1．D;2．B;3．D;4．B;
解析：

(1)	微波不会产生火或电，本身也不发出热量。根据第二段可知，微波引起食物中分子的活动而产生摩擦，而后产生热来把食物做熟。
(2)	根据文章第四段可知，利用微波做饭是1942年由Percy Le Spencer在做饭时偶然发现的。
(3)	根据第二段可知，微波引起食物中的分子活动，产生摩擦，然后产生热量把食物做熟。
(4)	文章前两段介绍了微波炉的优点和工作原理，后面则介绍了微波炉的发明，所以C项概括了前两段的内容，而A、D项概括了后面的内容，最全面的应是B项。