since when did you two become such good friends?中文意思

--Since when ________ each other --Oh I can't remember.A.did you know B.do you know C.you know D.have you known since when did/do you become so diligent是did 还是do?为啥 have .since did区别have .since have done?eg：I haven’t seen you since I’ve been back.I haven’t seen you since I was back. -When did you become a teacher?-In 1999.I___in this school since then. since when did you two become such good friends?中文意思 When did you study in france?A,Two years ago B,Since two years ago since you didn`t love me.why did you keep me waiting for a long time I don't get your postcard.When did you ____it? when did you start to play tennis?A.when I was ten b.since two years ago为什么 When did you leave? When did you coneback? when did you start skating?a,since i was five b since five years ago c when i was six d for six years选哪个,为什么? I began since that time when separated with you in the past,did not stop liking you you have been playing golf since you were 16 years old when did he begin to play golf ---Did you catch what the teacher said?No.She spoke so fast _______ I couldn't hear her very clearly.A.which B.that C.when D.since为什么 I've been collecting them since I was 5 years old 怎样提问可以when did you start collecting them? help-wanted是什么意思?对话背景：Woman:Since when did you read the Sunday Times?Man:Since I discovered its help-wanted section. When did you start skating?A.Since two years ago.B.Since I was nine years old.C.For six hours.D.Five years ago.