Look at the photo ,the boy__ them is my good friend.用on in berween to 选择填空并做语法说明

between

between
意思是：他们中的那个男孩儿是我的好朋友。
其实我认为这里among最合适。

between.
最好用among.
看照片,在他们中间的那个男孩儿是我的好朋友.
walked in between them走到他们中间
Something came between them.他们之间有误会
on 在.上;
in 在...内部;