Although the police thought he was the most likely one, _____ they had no exact proof about it, they could not arrest him.
| A．when | B．until | C．before | D．since |
. To everybody's surprise, the fashionable young lady ___________ to be a thief.
A. found out B. proved out C, put out D. turned out
Collecting stamps as a hobby___________ increasingly popular during the past fifty years.
| A．becomes | B．became | C．has become | D．had become |
The train was__________ to arrive at 11:30,but was an hour late.
| A．about | B．likely | C．certain | D．supposed |
Can you imagine what a girl will look like___________ she comes across a rat in her room?
| A．now that | B．though | C．in case | D．if |
--It starts raining outside.
--Oh, ____________!
| A．so it is | B．so does it | C．it does so | D．so it does |