Look! Several people in the crowd seemed .
| A．to be fighting |
| B．to have fought |
| C．being fought |
| D．having fought |
Only when he read the newspaper _____ 
the US President Obama would deliver a speech in his university．
| A．he knew | B．he had known |
| C．had he known | D．did he know |
He came to a point _____ there was no more road to follow, and before him he could see nothing but a thick forest．
| A．that | B．what | C．which | D．where |
_____ about the safety of her son, John’s mother looked upset．
| A．Concerning | B．Concerned | C．To concern | D．Concern |
Recent studies have shown that most US graduates receive cash as gifts, though the amount received ______ from person to person．
| A．prefers | B．promotes | C．varies | D．suffers |
We didn’t know you were in trouble at that time. ,we would have given you a hand.
| A．However | B．Besides | C．Otherwise | D．Anyway |