Question

14．和我同龄的学生们常常怀疑花这么多时间做家庭作业是否值得．Students of my age often doubt if it is worth spending so much time doing homework．．

Answer 1

分析 Students of my age often doubt if it is worth spending so much time doing homework．

解答 答案：Students of my age often doubt if it is worth spending so much time doing homework．表达的是经常性的动作故用一般现在时，主语students，和我同龄of my age，doubt怀疑，故Students of my age often doubt，后加if（是否）引导的宾语从句，be worth doing sth值得做某事，花时间做某事spend+时间+doing sth，故答案是Students of my age often doubt if it is worth spending so much time doing homework．

点评 doubt+宾语从句
　　（1）在否定句和疑问句中，doubt后面接that引导的宾语从句． 例如：
　　I don"t doubt that he can finish the task on time．我相信他能按时完成任务． Do you doubt that she will succeed？你怀疑她会成功吗？
　　（2）在肯定句中，doubt后面一般接whether或if引导的宾语从句． 例如：
　　I doubt whether they can swim across the river．我怀疑他们能否游过河去． He doubts if she will keep her word．他不敢肯定她是否会遵守诺言．