1.I have two sisters,both of them are doctors.
them 改为whom
2.That is the way which they work.
which改为that
3.Those have questions can ask the teachers for advice
Those后面+who
4.Who is the man who has white hairs?
第二个who改为that
5.I will never forget the days which we had a good time together at the sea
which改为when
有问题可以交流哦