These books should      to the library on time. 

– It’s difficult for the village children to cross the river to get to school.– We think a bridge ________ over the river.

—All the happiness was_________ when we heard the bad news from Yushu．—But what happened to you ?

Her life ____________  a lot in the last few years.

--- Many trees            around our school last spring.---The more trees, the better.