Many students signed up for the race in the sports meeting to be held next week.
| A．800-metre-long | B．800-metres-long | C．800 metre length | D．800 metres length |
She pretended ________the letter I wrote the day before yesterday.
| A．not to receive | B．not receiving | C．not to hear from | D．having not received |
Our father often told us in the past that _____is believing.
| A．to see | B．seeing | C．see | D．to be seen |
Is______necessary to change trains at Beijing?
| A．this | B．that | C．it | D．he |
When and where to build the new power station ______ yet.
| A．is not decided | B．are not decided | C．has not decided | D．have not decided |
_____is a good of exercise for both the young and the old.
| A．The walk | B．Walking | C．To walk | D．Walk |