There is a boy ____a tree in the garden.
A.plant    B.to plant    C.planting    D.plants
 ____the first photo.
A.on    B.in     C.at    
What is going on?翻译
（The young men） are swimming in the pool.（对括号内提问）
 ____   ____   ____  in the pool?
Mike is dancing to music.翻译