问题 多选题

下面有关硅的叙述中,正确的是(  )

A.硅原子既不易失去电子又不易得到电子,主要形成四价的化合物

B.硅是构成矿物和岩石的主要元素,硅在地壳中的含量在所有的元素中居第一位

C.硅的化学性质不活泼,在自然界中可以以游离态存在

D.硅在电子工业中,是最重要的半导体材料

答案

A.硅原子最外层4个电子,主要形成四价的化合物,故A正确;

B.硅是构成矿物和岩石的主要元素,硅在地壳中的含量在所有的元素中居第二位,故B错误;

C.硅在自然界中以化合态形式存在,故C错误;

D.硅在电子工业中,是最重要的半导体材料,故D正确.

故选AD.

完形填空

任务型阅读(从六个待选项中为每短话选择一个合适的标题,不必全部使用。)

Hollywood movies are regularly filled with sex and violence. They can be exciting films but sometimes all you want is a little light-hearted entertainment.

51.________ Have you heard of Bollywood? All singing, all dancing and unrealistic, it is the perfect alternative to normal Hollywood movies. Bollywood is the Indian film industry, based in Mumbai, formerly known as Bombay. Most Chinese school kids have probably never seen an Indian film. Yet Bollywood is the largest producer of films in the world. This year the Indian Filmgare Awards, Bollywood's Oscars, turn 50 years old.

52._________ The typical Bollywood movie usually has the following ingredients: a cup of romance, a tea-spoon of comedy, a dash of international sight-seeing, served with a huge slice of singing and dancing. There will also be one brave hero, one beautiful heroine and one baddie. The result is a fun-filled musical.

53._________ There is never any mention of politics, poverty or war. The actors change clothes and locations within a single song. But the audiences don’t mind. To Indian movie lovers, especially the poor, such films are a gateway to heaven and the stars are their gods. The films take them to a magical world away from their everyday troubles. The films tell them the impossible is possible and that true love conquers all.

54.__________ But, behind the beautiful scenes, Bollywood still emphasizes traditional family values. In most films, if two lovers want to break an arranged marriage, they can't just run away. They must win over their parents.

55.___________ So if you're tired of all that Hollywood actions, check out the following Bollywood films. They will take you to a brighter, cheerier and more colourful world, where it's still cool to dance around a tree and sing a love song.

A.Bollywood pays great attention to traditional values.

B.Bollywood is lees famous than Hollywood, and yet it produce the most films in the world.

C.Bollywood films are full of ideal things and free of daily worries.

D.Bollywood is a decent refreshing replacement for those over-stimulating Hollywood films.E. Bollywood has gradually won its reputation on the world stage.

F. Bollywood films are mostly comic romances with light-hearted incidental music.

单项选择题