语法填空。

No one is alone in this world. （volunteer）is becoming more and more popular among people. It is said that there （be） more and more younger volunteers in China in a few years, but there is no need （wait）! Please try （become）a volunteer today!

Yang Lei and Xu Hui come from the same city. Both of them like to spend their free time （help）other people. Yang Lei often goes to the hospital. There he can talk to patients and （read）to patients. Xu Hui （teach）students in a poor mountain village in Gansu Province as a volunteer. She used （be）a teacher in a big school in Beijing. Life there （stay）very hard, but it is always full of joy. So she doesn't mind （live）there. She loves her students.

I.