Only when _______ 30 years old ______ to learn English.
| A．was he; did he begin | B．he was; he began | C．he was; did he begin | D．was he; he began |
We must take measures to protect endangered wildlife ______it is too late.
| A．now that | B．as long as | C．unless | D．before |
People living in the area where there is a lack of electricity often keep a supply of candles_______power failure.
| A．in case of | B．once | C．even if | D．in course of |
_______ all his followers dead，the captain was taken by his enemy.
| A．For | B．As | C．Because of | D．With |
_Your suit won’t be ready_______Friday.You can collect it next Monday.
| A．on | B．by | C．till | D．for |
_The beginning of agriculture was a big step in human progress _______which nothing could compare until our information age.
| A．in | B．for | C．with | D．by |