We should ( )water.Turn off the shower while we( )our hair.A saved;washed Bsave;washingB save;are washing D saved;wash为什么

问题描述:

We should ( )water.Turn off the shower while we( )our hair.
A saved;washed Bsave;washing
B save;are washing D saved;wash
为什么

B save;are washing

B should+动词原形,while后用动名词

个人感觉没有一个对的
前面只有用原型save
后面应该是选完头后后,一般过去式,所以答案为
save,washed