_____ of the students who took part in the military training is 450.
| A．A number | B．A lot | C．Lots | D．The number |
There is said to be no medicine for a cure _____ lung cancer.
| A．for | B．of | C．at | D．about |
_____ your attention focused on practicing, and you can reach your goal of becoming an excellent pianist.
| A．Keep | B．Keeping | C．To keep | D．If you keep |
I am so excited! At this time tomorrow I _____ to Rome, my dream city!
| A．fly | B．will fly | C．will be flying | D．have flown |
The singers _____ from the whole country are expected to bring us a wonderful performance this weekend.
| A．selecting | B．selected | C．having been selected | D．to select |
_____ the government recovers the vehicle purchase tax and the oil prices go up continuously, the sales of the vehicle in China are still increasing every year.
| A．When | B．Once | C．Since | D．While |