1936, in reference to session musicians; 1937, in reference to union action; 1941, in reference to student protests. From the verbal phrase; see sit (v.) + in (adv.). To sit in is attested from 1868 in the sense "attend, be present;" from 1919 specifically as "attend as an observer."
权威例句
1. Let's sit down and then you can say what's up.
咱们先坐下来,然后你把事情告诉我。
2. We can't just sit by and watch you throw your life away.
我们不能眼睁睁地看着你毁掉自己的生活。
3. Now sit down and make yourself comfortable. You must be very tired.