than有两种词性,1.连词:即she is more athletic than I am .或she is more athletic than I.第二句为am省略; 2.介词,则 she is more athletic than me.故用me也是对的。初中课本有很多相类似的句子如: He is taller than me./I (am).
...more...than...前后接的是并列的成份,前面是she is是物主代词加be动词,后面也是I am 物主代词加be动词.
...more...than...前后接的是并列的成份,前面是shi is代词加BE动词,后面也是I am代词加BE动词.
希望能帮到你