用介词填空 there was a big smile [ ]his face

the little boy ran in and there was a big smile on his face there was a pleasant smile on his face There was a pleasant smile on his face. A big smile appeared on his face. He wears a big smile on his face .There is no d____ that he There was an u( ) smile on his face Benny said,with a big smile on his face是什么意思? Sally is very happy.There is a big smile to her face .为什么要用t There is -a---- a charming smile on his face __a big smile on his face there is a relaxed smile on his face.为什么用relaxed?不用relaxing? A smile ( ) on his face.