Ann:I'm going to take a bath.Bill:Make sure you wash up well

Ann:I'm going to take a bath.Bill:Make sure you wash up well 请问wash
洗澡时还要洗手洗脸吗
若是,则意思为ANN:我准备洗个澡
BILL:好好洗手洗脸
使用wash up时只能在洗脸,洗手时用吗?