阅读理解

A

　　 Dolphins (海豚) are not fish but mammals (哺乳动物)．They live in groups, and speak to each other in their own language. In this way they are like many other animals, like bees. But dolphins are very different from almost all land animals. Their brain (脑) is nearly the same size as humans', so they are the cleverest animals. And they live for 20 to 30 years.

        But what does the dolphin look like？The dolphin has teeth, and eats fish. It can grow up to three and a half metres long. Its nose is very long. Like some other animals, the dolphin uses sound to find its way. They make sound to talk to each other and to help find food. We now know they don't use their ears to listen to the sound, but the jaws (颚)．

　　　Dolphins are friendly to people. They often save people in the sea. So many people like them.

填入下面横线处的句子，与上下文前后连贯、音节和谐的一组是（  ）
埋伏和照应需要惨淡经营。埋伏处要能轻轻一笔，若不经意；_______。要使读者看不出斧凿痕迹，只觉得________，如一丛花，如一棵菜。虽由人力，却似天成。如果看出来这里是埋伏，那里是照应，________。
①照应处要顺理成章，水到渠成
②照应处要水到渠成，顺理成章
③清清爽爽，简简单单
④自自然然，完完整整
⑤便成死症
⑥便太浅显

My mother bought a lot of things last Weekends.(改为一般疑问句)

____  ____ mother ____ a lot of things last Weekends?

诗歌鉴赏。

湖（即西湖）上

宋·徐元杰

花开红树乱莺啼，草长平湖白鹭飞。

风日晴和人意好，夕阳箫鼓几船归。

对比是学习化学的重要方法.下列关于 与CO的比较错误的是(       )