While mother (put)Cathy to the bed ,the door bell ( )(ring)适当形式填空

问题描述:

While mother (put)Cathy to the bed ,the door bell ( )(ring)适当形式填空

put
is ring

be 动词

was putting rang

puts will ring,这是一个条件状语从句,从句用一般现在时,主句用一般将来时

应该是 puts 和 rings
While mother (puts) Cathy to the bed, the door bell (rings).
两个都是现在式,而且前後应该相对应.

putting,rang

不是的 这是一个时间状语从句 put /is ringing

is putting,,,rings
正在做某事时。。。怎么样。。。