31. In the center of the room stood a table with a _____ lamp on it, so it is very
bright in the room.
| A．lighted | B．lighting | C．lit | D．Light |
.__________ he had not hurt his leg, John would have won the race.
| A．If | B．Since |
| C．Though | D．When |
.I won’t call you, __________ something unexpected happens.
| A．unless | B．whether |
| C．because | D．while |
. He was told that it would be at least three more months __________ he could recover and return to work.
| A．when | B．before |
| C．since | D．that |
.Most birds find it safe to sleep in the trees, but __________ they have eggs or young chicks, they don’t use a nest.
| A．why | B．how |
| C．unless | D．where |
. Leave your key with a neighbor __________ you lock yourself out one day.
| A．ever since | B．even if |
| C．soon after | D．in case |