英语填词，很简单！

in of in at

in
of
on
at

In
of
in
at

two pencils are （in ） the pencil case。
this is a photo （ of ） my friend。
I can see some girls （ in ）the picture。
look （at ）the girl。she is my sister

two pencils are (in) the pencil case.
this is a photo (of) my friend.
I can see some girls (in) the picture.
look (at) the girl.shiis my sister.

in
of
on
at