单项选择题A．Every year people add large amount of fertilizer to the soil.B．The water in the Nile overflowed its banks once a year.C．There are no tides in the Mediterranean.D．The Nile rises and falls once a year, leaving the land a layer of rich, black soil.

单项选择题A．They are not active animals.B．The weather is too drought and sweltering.C．They have nothing to eat during the summer.D．Their body temperature is not high enough.

单项选择题A．The American team captured the gold medal.B．The Japanese team won the game because more people arc in favor of them.C．It’ s net surprising that the Japanese team won the game.D．The Japanese team won the game by chance.

单项选择题A．He worked late.B．His car broke down.C．He forgot about the appointment.D．He met someone else on the Way.

单项选择题A．They are the same action.B．They are two separate actions.C．They are two actions carried on entirely by the eyes.D．They are several actions that take place at different times.