---- Did you visit the Big Ben in London?
---- No, we ______ it, but we spent too much time shopping.
| A．could visit | B．could have visited | C．must ahave visited it | D．can have visited |
The doctor advised Lisa strongly that she should take a holiday but _______ didn’t help.
| A．it | B．which | C．what | D．this |
Miss. Gao _______ in the library for three years. But now she is a teacher.
| A．worked | B．has worked | C．had worked | D．has been working |
I'm sorry you've been waiting so long, but it'll still be some time _______ Sundance gets back.
| A．until | B．before | C．after | D．since |
－Have you been to Liuyang?
－No, I'd like to, _______.
| A．too | B．either | C．yet | D．though |
A new bridge _______ across the river in Changsha and it is expected to open next year.
A. is built B is being built C. are built D. has been built