________ time went by, small clever animals covered the earth and have become the most important animals on the planet.
| A．With | B．As | C．Because | D．During |
They discovered the cause of the fire accidentally. They discovered it _______.
| A．fortunately | B．by chance | C．all of a sudden | D．on purpose |
They lost their way in the mountain and _________ made matters worse was _______ it was getting dark.
| A．that, because | B．what, that | C．/, because | D．that, that |
He was embarrassed. He felt _____________.
A. shy B. hot C shameful D. uncomfortable
The hotel is very comfortable, because it has successfully ______ the old and the new styles.
| A．combined | B．joined | C．connected | D．related |
The Chinese people consider dragons as a ____ of China.
| A．sign | B．mark | C．character | D．symbol |