Across North China in the world, namely the Great Wall.
| A．the longest wall runs | B．runs the longest wall |
| C．does run the longest | D．does the longest wall run |
You may ask the teacher for help ____ difficulty.
| A．in case of | B．in the case of | C．in any case | D．in no case |
The train ____ at present speed until it reaches Beijing.
| A．is running | B．will be running | C．will have run | D．has run |
Before becoming a pilot, he spent quite a long time ____.
| A．to be trained | B．being trained | C．training | D．to train |
Yang Liwei’s journey into ____ space took him 600,000 kilometres in ____ orbit, around the earth 14 times, in just over 21 hours.
| A．a, an | B．the, an | C．不填，不填 | D．the, the |
____ it is to skate on real ice in winter!
| A．What fun | B．What a fun | C．How fun | D．How a fun |