单项选择题
A．Fred is planning a trip to Canada. B．Fred usually flies to Canada with Jane. C．Fred persuaded Jane to change her mind. D．Fred likes the beautiful scenery along the way to Canada.
A．The woman is strict with her employees. B．The man always has excuses for being late. C．The woman is a kind-hearted boss. D．The man’s alarm clock didn’t work that morning.
A．Lack of oxygen. B．Overgrowth of water plants. C．Low water level. D．Serious pollution upstream.