____ difficult the work may be, we must go all out to finish it ahead of time.
| A．Whatever | B．However | C．How | D．What |
______________ is quite obvious that there is no water on the Mars.
| A．There | B．It | C．That | D．This |
To qualify yourself for this kind of new job, I recommend that you ________ some on-line course.
| A．to take | B．taking | C．take | D．would take |
Students are encouraged to _________ the design competition for robots at the university.
| A．take part | B．operate | C．join to | D．participate in |
I have never imagined _______ such a good hotel in this town.
| A．there having | B．there’s being | C．there being | D．there have |
Many applicants stood 
outside the manager’s office, nervously waiting _________ for the job.
| A．to choose | B．being chosen | C．choosing | D．to be chosen |