题目

在浅海中，牡蛎与鱼类、节肢动物、棘皮动物等所有生物生活在一起．这些生物构成了（）       A．                       群落                            B． 种群                      C．   生态系统       D． 生物圈 答案：A完成短文，用下面所给词的适当形式填空，每词只用一次。 　　John was ten years old. One day his friend Tom said to him, “I'm going 1 a birthday party next Sunday. Would you like to come to 2 party?”“Sure, I'll be glad to.” 3 John. 　　Before John went to the party, his mother told him,“Now John, don't forget 4 polite. Don't ask for food until someone 5 it to you.” 　　“All right, Mum” John answered and 6 to Tom's house on his new bike. 　　There were a lot of 7 at the party. They played together 8 for hours. Then Tom's mother gave them some food. But she forgot to give John any. John 9 10 for ten minutes and then he held his plate up in the air and said 11 “Does anyone 12 a nice and clean plate?”