.../trouble /difficulty (in ) doing sth have fun (in ) doing sth have a great time (in ) doing sth be happy to do sth
...t start the work until all the preparations has been made.1.在时间状语从句中,表示将来已完成的被动动作动作,用现在完成时的被动语态代替将来完成时代的被动语态。这里是说不管主句是什么时态,从句都要用现在完成时的被动语态吗?2....
下面两句用的都是单数,但可以用复数吗? One plus six equals seven. 一加六等于七。 Since when does the $42 plus $5 service charge come to $48? 从什么什候开始42美元加5美元的服务费等于48美元了?
请问各位老师,非限制性定语从句whose能变为名词+of which/whom或of which/whom+名词吗,还是只有限制性定语从句能这么变?