when your order____ ,we will send you another e-mail.A ships Bwill ship C has been shipped D has shiped我知道这道题肯定要选C 被动语态,但是为什么要用完成时态呢?如果说is shipped

when your order____ ,we will send you another e-mail.A ships Bwill ship C has been shipped D has shiped我知道这道题肯定要选C 被动语态,但是为什么要用完成时态呢?如果说is shipped when you lose your When is your birthday? when is your birthday? when is your national when i looking your when i looking your when do your homework When is your birthday? When are your classes? when dose your trouble When in your birthday? When ia your Independence when was your school when is your breakfast? when is your birthday? when your mother comes 还是when your mother will come “When was your last trip?