The lady was so absorbed in her job that she didn't hear a customer ________ at the door.
| A．to knock | B．knocking |
| C．be knocked | D．knocked |
The fans were told that all the tickets had been sold out, ________they had waited outside the booking office for so long.
| A．as | B．since |
| C．unless | D．though |
______ the early train, you’ll have to get up early and rush in a taxi.
| A．caught | B．catching |
| C．catch | D．to catch |
It has been cold and windy recently. If only it ______sunny and clear now!
| A．is | B．should be |
| C．were | D．being |
Madame Curie(居里夫人) contributed all his life ______ radium(镭) so that she has earned respect from people all over the world.
| A．to study | B．to studying |
| C．study | D．studied |
______the urgent problem caused by wars and conflicts, the UN helps countries with other problems.
| A．Except | B．Apart from |
| C．Apart for | D．Except for |