The reason I have to go is my mother is ill in bed.
| A．why...why | B．why...because |
| C．that...because | D．why...that |
—China is developing rapidly.
—Yes, to make our country more prosperous, we should firmly the principle of scientific development.
| A．contribute to | B．subscribe to | C．stick to | D．turn to |
Saving and recycling are long-term projects _______ determination matters a great deal.
| A．that | B．which | C．whose | D．where |
Jack wasn’t saying anything，but the teacher smiled at him ________he had done something very clever．
| A．as if | B．in case |
| C．while | D．though |
US President Barack Obama ________ a national speech at the 10th anniversary of 9/11 terror attacks．
| A．addressed | B．delivered |
| C．spoke | D．recited |
Mistakes don’t just happen; they occur for a reason. Find out the reason, and then making the mistake becomes ______.
| A．favorable | B．precious | C．essential | D．worthwhile |