The project alongside with the experiment we had once devoted so much time __________ perfectly.
| A．to work out | B．to working out |
| C．to worked out | D．has worked out |
Statistics show that men have _____ as women do for every mile they drive．
| A．serious accidents as twice many | B．twice as many serious accidents |
| C．twice serious accidents as many | D．serious accidents as many twice |
Leave it to me! I feel much more _____ about myself and my abilities these days．
| A．confident | B．energetic | C．generous | D．curious |
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 |