A:1+i
B:1﹣i
C:﹣1+i
D:﹣1﹣i
某单位员工按年龄分为A,B,C三级,其人数之比为5:4:1,现用分层抽样的方法从总体中抽取一个容量为20的样本,已知C组中甲、乙二人均被抽到的概率是125则该单位员工总数为 ( )
He hasn't decided _______ to go by bus or by train.
My mother is________than her child. ( )