I will work as hard as I can _____ for the final exam.
| A．prepare | B．to prepare | C．preparing | D．prepared |
By the end of last week, nearly 80 percent of the work .
| A．have finished | B．had been finished | C．will be finished | D．was finished |
We used to mistake that heavy objects fell faster than light .
| A．the ones | B．those | C．ones | D．these |
Keep yourself open we can experience the great joy that friendship can bring.
| A．as if | B．so that | C．even though | D．ever since |
Look at the timetable. Hurry up! Flight 9013 to Changsha off at 7:30.
| A．took | B．takes | C．will be taken | D．has taken |
Microblogs experienced rapid growth in 2013 in China, with its operators, users and visitorsseveral times.
| A．increase | B．increased | C．increasing | D．to increase |