The soil is becoming poor because farmers here mostly use only one kind of chemical fertilizer for several years________.
| A．in a row | B．on a large scale |
| C．at random | D．to a degree |
According to the rules and regulations, all payments ________ be made in cash in the shopping center.
| A．shall | B．can |
| C．must | D．should |
—Show me your permit, please.
—Oh, it's not in my pocket. It ________.
| A．must have fallen out | B．might fall out |
| C．could fall out | D．should have fallen out |
People love the convenience of bottled water, but if they ________ the problem it causes, they ________ try carrying water in a reusable steel container instead of plastic.
| A．realized; will | B．had realized; will |
| C．realized; would | D．have realized; would |
If you want somebody to go window shopping with you, why not try calling Marie? —she ________ be home by now.
| A．shall | B．should |
| C．will | D．would |
—How was your trip to Yancheng last week?
—Wonderful! I only felt sorry that I ________ the nature reserve of redcrowned cranes, but the weather was awful.
| A．could visit | B．could have visited |
| C．might visit | D．might have visited |