will you stay for some more days?sorry I （） my mother called me to go back at once
问题描述：
will you stay for some more days?sorry I （） my mother called me to go back at once
Amustn't B may notCcan't Dwouldn't
并说明理由
答
C
这里表示“做不到” 因为母亲叫我马上回去（下文）