Dear friends ,life is short .So do not keep the box of your love and friendship closed up _______your friends are gone .

Dear friends ,life is short .So do not keep the box of your love and friendship closed up _______your friends are gone .Speak cheering words while their ears can hear them and while their hearts can be made happier
A until B though C if 答案给的是A 我选的是C 不太明白,