during=?or=?at once after=?三年前:_____ _____ _____ _____ _____

问题描述:

during=?or=?at once after=?三年前:_____ _____ _____ _____ _____

during=in time of
or=otherwise(当否则的意思的时候)
at once =rignt now、right away
after=in the back of(当意思为在...之后)
三年前:three years ago