_____ you understand the rules of the game, you will enjoy it.
| A．Before | B．Even if | C．Once | D．While |
She finds ＿＿＿＿＿＿ boring ＿＿＿＿＿＿ at home.
| A．it； staying | B．that； being stayed | C．this； to stay | D．it； stayed |
＿＿＿＿＿＿ for the free tickets, I would not have gone to the films so often.
| A．If it is not | B．Where it not | C．Had it not been | D．If they were not |
It’s the third time ＿＿＿＿＿ arrived late this month.
| A．that you | B．when you | C．that you’ve | D．when you’ve |
Our classroom is very clean. Do you know who＿＿＿cleaned it?
| A．was it that | B．it was that | C．was it who | D．he was |
—— Was that the new comer who walked by?
—— ＿＿＿＿＿.
| A．It must be that | B．It must have been | C．He must be | D．This must have been |