by turns, in turn
这两个词组都与turn有关。
by turns: 意思是“轮流地”、“交替地”、“忽而...忽而...”（ one after another； alternately or in rotation）
- we read the poem by turns.
我们轮流读这首诗。 - they sang songs by turns.
他们轮流唱歌。 - he grew pale and red by turns.
他的脸一会儿红一会儿白。
in turn: 意思是“依次相继地”（each in due succession）
- we sang the song in turn.
我们依照次序唱歌。 - we were summoned in turn to see the judge.
法官依次召见我们。
