题目

In Canada you can find dogs, cats, horses, etc. in almost every family. These are their pets. People love these pets and have them as their good friends. Before they keep them in their houses, they take them to animal hospitals to give them injections(注射) so that they won’t carry disease. They have special animal food stores, though they can get animal food in almost every kind of store. Some people spend around two hundred Canadian dollars a month on animal food. When you visit people’s houses, they would be very glad to show you their pets and they are very proud of them. You 将细胞的各部分结构与它们对应的功能连接起来细胞膜----动力车间叶绿体----遗传信息库线粒体----控制物质进出细胞核----使光能变成化学能细胞壁----保护并支持细胞．