- Have you known each other for long?- Not very long, _______ we started to work in the company.
A:after
B:since
C:when
D:before
求证:
下列词语中没有错别字的一项是( )
I'm hungry, Mum. May I have _________?
若复数z=1+i1-i+m1-i(i为虚数单位)为非纯虚数,则实数m不可能为( )