Based on a true story, the film shows a hero racing ______ time to get back the stolen papers.
| A．behind | B．against |
| C．about | D．at |
Father _____for London on business upon my arrival, so I didn’t see him.
| A．has left |
| B．left |
| C．was leaving |
| D．had left |
The father as well as his three children ____skating on the frozen river every Sunday afternoon in winter.
| A．is going |
| B．go |
| C．goes |
| D．are going |
Although the causes of cancer _____, we do not yet have any practical way to prevent it.
| A．are being uncovered |
| B．have been uncovering |
| C．are uncovering |
| D．have uncovered |
At this time tomorrow ____over the Atlantic.
| A．we’re going to fly |
| B．we’ll be flying |
| C．we’ll fly |
| D．we’re to fly |
Susan decided not to work on the program at home because she didn’t want her parents to know what she_____.
| A．has done |
| B．had done |
| C．was doing |
| D．is doing |