The course normally attracts 20 students per year, _____ up to half are from abroad.
| A．of whom | B．for whom | C．in which | D．with whom |
For many students, math is not something that comes _________. It takes effort.
| A．regularly | B．possibly |
| C．automatically | D．secretly |
The training program can give you a lift at work, ______ increase your income
by 40%.
| A．so much as | B．as well as |
| C．so long as | D．as soon as |
A recent research shows that there _____ volcanic activities on the moon and Mars. However, they no longer exist now.
| A．had been | B．has been | C．were | D．would be |
If she had known what lay ____ for her, she would never have agreed to go.
| A．in demand | B．in debt |
| C．in place | D．in store |
The frozen waterfall has attracted floods of tourists to ____ the natural beauty.
| A．cherish | B．admire | C．observe | D．discover |