Mr Smith will come back in three days.对 in three days提问 ______ ______ _______Mr Smith come back They left Beijing after two weeks.对 after two weeks提问 ______ ______ they _______Beijing 翻译.我想要两张纸 I want two _____of_____.我们对海滩上所有的污染感到吃惊 We was _____by all the _______on t he beach.我通常乘地铁上学 I go to school ______ _______.