1. volunteer
前加to2. set → setting 3. cheer up them → cheer them up
4. could I → I c
ould5. Be → Being
下列各句中均有一处错误，请指出并改正。 1. He asked these students volunteer in
1. volunteer
前加to2. set → setting 3. cheer up them → cheer them up
4. could I → I c
ould5. Be → Being