用所给动词的适当形式填空（共10小题；每小题1分，满分10分） 小题1:The place was crowded. Mr. Brown didn't know where_______ (park) his car. 小题2:-The windows are dirty. -I know. They_______ (not clean) for weeks. 小题3:We can never follow the fashion because it_______ (change) all the time. 小题4:Before John went to the USA, he_______ (be) a famous director in Hong Kong for many years. 小题5:In order to make the river clean, people should_______ (prevent) from throwing rubbish into it. 小题6:_______ (get) there on time, you need to get up early tomorrow morning. 小题7:I am very angry because I _______ (not receive) the things that I ordered online. 小题8:Nowadays people prefer_______ (shop) online to buying things in stores. 小题9:He told me that he_______ (return) my book before Sunday, but he didn't. 小题10:What a waste of time it is_______ (spend)so much time playing computer games!