_______ his studies, he started travelling in China.
| A．As soon as finish | B．As soon as finishing |
| C．Upon finishing | D．Upon finish |
Sarah pretended to be cheerful, ______ nothing about the argument.
| A．says |
| B．said |
| C．to say |
| D．saying |
The lecture, ______ at 7:00 pm last night, was followed by an observation of the moon with telescopes.
| A．starting |
| B．being starting |
| C．to start |
| D．to be started |
Marco Polo is said to have sailed on ______ Pacific Ocean on his way to Java in ______ thirteenth century.
| A．the; a |
| B．a;/ |
| C．/; the |
| D．the; the |
The other scientists ______ to her ideas with a mixture of criticism and silence.
| A．agreed |
| B．reacted |
| C．approved |
| D．commented |
The country itself didn't have enough gas because of the war，so the government decided to ________ its gas supplies to other countries.
| A．hide away |
| B．cut off |
| C．insist on |
| D．break up |