Michelle advised me not to change my mind easily, but the way of teaching I ________ greatly in the past six months．

was used to have changed

used to change

used to changing

was used to has changed

If you ________ her, we ________ out what was happening．

didn't phone; would never found

hadn't phoned; would never find

didn't phone; would never have found

hadn't phoned; would never have found

It ________ he ________ his office．

was until the clock struck 12 when; didn't leave

wasn't until the clock struck 12 when; leave

wasn't until the clock struck 12 that; leave

wasn't until the clock struck 12 that; left

Our city has developed into a big city, which is ________ it used to be．

four times larger than that

four times the size of what

four times the size larger than what

as four times the size as that

In front of our house ________ we used to swim．

a river lies that

does a river lie where

lies a river which

lies a river where

Faced with a bill for ＄10,000, ________．

John has taken an extra job

the boss has given John an extra job

an extra job has been taken

an extra job has been given to John

After a thorough investigation, the policeman declared that the blow on the victim's head ________ from behind．

should have been made

must have been made

would have been made

ought to have been made

All the people wondered eagerly ________ caused the serious building fire in Jiaozhou Road in Shanghai．

what was it that

what it was that

how it was that

why it was that