下列各句中均有一处错误，请指出并改正。

1. He asked these students volunteer in the after-school study program.                  ___________

2. My uncle wants to help the poor people in the city by set up a food bank.           ___________

3. Some of my classmates volunteer to sing for the old people to cheer up them.     ___________

4. What do you think could I do for you?                                                               ___________

5. Be a volunteer is great.                                                                                       ___________

胃癌的盆腔转移是（）

A．淋巴道转移

B．直接蔓延

C．种植性转移

D．血道转移

E．椎旁静脉系统的转移