一、sell做不及物动词时,就是它后面没有接宾语的时候,常常用主动表被动.
e.g.The kind of book sells well.
sell做及物动词时,就是它后面接宾语的时候,会用典型的被动语态表被动.
e.g.He sold his house.
His house was sold by him.
二、keep同sell的道理一样.
一、sell做不及物动词时,就是它后面没有接宾语的时候,常常用主动表被动.
e.g.The kind of book sells well.
sell做及物动词时,就是它后面接宾语的时候,会用典型的被动语态表被动.
e.g.He sold his house.
His house was sold by him.
二、keep同sell的道理一样.