问题
Have you ever visited the Water Cube?— YesWhen I served as a volunteerin Beijing, I it twice.[ ]
A: have visited
B: visited
C: had visited
D: had been visiting
B: visited
C: had visited
D: had been visiting
正确答案是：
同类题型
You’re not angry then —_____ I’ve never laughed so muchin my life
Hello, I _______ to ask if I can book two tickets for tonight’s film.— Sorry, we’ve already sold out
Are those_________ —-No, they aren’t. They are _________ .
David is imaginative . He usually good ideas . — Yes , He’s used to using his head at all times
She _________ high and tries hard to make her dream come true.