We have 20 more trees------.(plant)怎么填

We have 20 more trees------.(plant)怎么填 why should we plant more trees? We should plant more trees this year.怎么变被动语态? We promise that we will plant more trees.(意思相同) we should plant more trees ,and..then the The more trees we plant,the______(good)our environment is. ----more trees we plant,----better environment there will be we must plant more trees to ____ our planet greener. We should plant more trees to make the air_____.(clean) we plant trees every we plant trees ( )March 12th中间填什么介词 "We can plant trees in spring."对"plant trees"提问,怎么提?