【单选题】— Do they play tennis? — Yes, they play tennis ____ you do.
【单选题】I’d like to do something for you ____ everything you’ve done for me.
【单选题】因链轮具有多边形的特点,链传动的运动表现为( )
【单选题】因链轮具有多边形特点,链传动的运动表现为( )。
【简答题】定义“正对数”: ,现有四个命题: ①若 ,则 ; ②若 ,则 ; ③若 ,则 ④若 ,则
【简答题】In August we play tennis every day. In August we play tennis all day. ____