He talked about the classmates and the school （ ） he had visited.
（A）who
（B）that
（C）which
（D）about which
A teacher of English and class teacher （ ） us something about volunteer workers.
（A）are telling
（B）is telling
（C）are given
（D）were given
Mayor as well as volunteer workers （ ） the newly - built stadium.
（A）is cleaning
（B）are cleaning
（C）were cleaning
（D）have cleaned
