1 It seems that she likes you(主语从句)--------简单句：She seems to like you
2 It seems that she is reading something--------------She seems to BE READING something.
3 It seems that she has done her work.----------------She seems to HAVE done her work
4 It seems that she was here last week.-------------------She seems to HAVE BEEN here last week.
5 It seemed that she knew everyone there--------She seemed to KNOW everyone there.
it (形式主语)seems （谓语）that she likes you （真正主语） that是引导词,she- - -you是真正主语