简单句和并列句中用some/none of them
例如：There are ten people in the room.Some of them are children.
There are ten people in the room,and some of them are children.
复杂句中,非限制定语从句部分用 some/none of which/whom
例如：There are ten people in the room,some of whom are children.
There are ten apples on the table,some of which are green.