When the news came ________ the war broke out，he decided，to serve in the army.
| A．since | B．which | C．that | D．because |
The population of this city, forty percent of which __________, __________ 15% in the last three years.
| A．are Germans; has risen by |
| B．are Germen; has fallen by |
| C．is Germans; have increased to |
| D．is Germans; has been reduced by |
A good teacher should encourage his students to __________ the knowledge by themselves instead of just copying and memorizing what the teacher said in class.
| A．expand | B．observe |
| C．digest | D．react |
—Could I ask you a rather personal question?
—Sure, __________.
| A．pardon me | B．go ahead |
| C．good idea | D．forget it |
People try to avoid public transportation delays by using their own cars, and this __________ creates further problems.
| A．in short | B．in case |
| C．in doubt | D．in turn |
The __________ look on his face showed that he hadn't expected it.
| A．astonished | B．astonishing |
| C．being astonished | D．having astonished |