选用介词at,in,on填空
问题描述：
选用介词at,in,on填空
___the wall(在墙上) ___the ground(在地面上) ___the river(在河上) ___the left(在左边) ___ the moon(在月球上) ___the lake(在湖面上) ___the farm(在农场) ___the earth(在地球上)
答
on
on
on
in
on
in
on
in