The best way of learning a language is using it .The best way of learning English is talking in English as much as possible. Sometimes you'll get your words mixed up ( 混合)and people will not understand you .Sometimes people will say things too quickly and you can't understand them. But if you keep your sense of humor (幽默感),you can always have a good laugh at the mistakes you make(你所犯的错误). Don't be unhappy if people seem to be laughing at your mistakes（错误）. It is better for people to laugh at your mistakes than to be angry with you. because they don't understand what you are saying .The most important thing for learning English is : “Don't be afraid of making mistakes because everyone makes mistakes. ”

   The early history of the city of Rome involves Romulus and Remus，two orphan boys who，legend says，were raised by a she-wolf．The boys'mother had been murdered by an evil king and the two babies tossed into the river Tiber．When the wolf found them they had washed up on the shore．She perhaps took pity on the crying of the babies and，gently picking them up in her teeth，she carried them back to her cave and fed them on her milk．The boys grew bigger and stronger and，eventually，were found by a herdsman who took them home．He and his wife raised the boys like their own children．When they reached manhood they sought revenge on the king who had killed their mother and driven them from their home．
   They decided to build a city．Unfortunately，they argued over the appropriate site and Romulus killed his brother Remus．Romulus ruled this city — called Roma — for thirty-seven years．
   The city of Rome is one of the most popular tourist attractions in the world．If you travel there you can see a statue of the two baby boys feeding from their mother - the wolf．

考古学家在商丘某地的一处古墓的随葬品中，发现了青铜器、铁制农具及珐琅彩瓷器。这座墓葬最早可能出现于（    ）

动物能够维持____；动物能够帮助植物____，使这些植物能够顺利地繁殖后代；动物能够帮助植物传播____，有利于扩大植物的分布范围．