用不定词填空(快!）1、there are two pictures on the wall.___is the pic

用不定词填空(快!）
1、there are two pictures on the wall.___is the picture of the great wall ,___is the picture of the summer palace.
2、my sister bought two dresses for me.___is white,___is yellow.
3、lily is my sister.i have ___ sister.
4、jim and tom helped___.
5、there are many students in the classroom.some are reading books,___are writing latters.