since有几种意思？

since(sns)

adv.
1. From then until now or between then and now: They left town and haven't been here since.
2. Before now; ago: a name long since forgotten.
3. After some point in the past; at a subsequent time: My friend has since married and moved to California.
prep.
1. Continuously from: They have been friends since childhood.
2. Intermittently from: She's been skiing since childhood.
conj.
1. During the period subsequent to the time when: He hasn't been home since he graduated.
2. Continuously from the time when: They have been friends ever since they were in grade school.
3. Inasmuch as; because: Since you're not interested, I won't tell you about it.

既然
从..开始
由于

之后;自....以来;以前;....以来;从上次...以来;...的缘故;因为...;自从;打;既;自

since
[sins]
adv.
以后, 后来, 以前
prep.
自从, 自...以来
conj.
自...以后, 自...以来, 因为, 既然

连接词
★ 1. 主句中动词用现在完成式时， since 所引导的子句须