The nutrients in _____falls into the ocean quickly become available to other living creatures.

—Which type of car do you like better?—       ．They are both expensive and high emission（高排量）．

 —_______ do you have a sports meet at your school?—Once a year. 

When you are reading fast，your eyes will be one or two word groups ahead of______ your mind is taking in.

—Mary，new copies of Harry Potter are on sale now． —Great! Let’s go and buy       this afternoon．