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1)since　/ sɪns; sɪns/ prep

(used with the present or past perfect tense 与现在完成时态或过去完成时态连用) from (a specified time in the past) till a later past time, or till now 从(过去某时间)以来﹑ 以後或到现在: I haven't eaten since breakfast. 我吃了早饭後到现在还什麽都没吃呢.

例：She's been working in a bank since leaving school. 她中学毕业後就一直在一家银行工作.

例：He had spoken to her only once since the party. 自从那次聚会以来, 他只跟她说过一次话.

2)since conj

(used with the present perfect, past perfect or simple present tense in the main clause 与主句中的现在完成时态﹑ 过去完成时态或一般现在时态连用) from (a specified event in the past) till a later past event, or till now 从(过去某事)以来﹑以後或到现在;

例：Where have you been since I last saw you? 自从我上次见到你以後, 你到哪儿去了?

例：It was the first time I'd won since I'd learnt to play chess. 自从我学会下国际象棋以来, 这是我第一次赢.

例：How long is it since we visited your mother? 自从我们看望你母亲以来到现在有多长时间了?

because; as 因为; 既然; 由於: Since we've no money we can't buy a new car. 因为我们没钱, 没法买新汽车.

(idm 习语) ever since =>ever. since adv (used with the present or past perfect tense 与现在完成时态或过去完成时态连用) from a specified time in the past till a later past time, or till now 从过去某时间以来﹑ 以後或到现在;

例：He left home two weeks ago and we haven't heard from him since. 他两星期以前离开了家, 到现在我们一直没有他的消息.

例：She moved to London last May and has since got a job on a newspaper. 她去年五月到伦敦, 此後一直在报社工作.