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
If I ________ your advice then, I think that the crops could be growing better.
A．took B．would have taken
C．had taken D．have taken
