single out和pick out的区别

single out 是成语.
single out 意味着（基于性别,种族,成绩,或其他因素）选出给予特别对待,重点是特别对待,
而 pick out 只有挑选的意思：
例：
Mary was not just picked out from a group of students to be class prefect.She was singled out for her outstanding performance.
Jane was always singled out for special treatment because she is the prettiest in the class.

single out 只有挑出或选出的意思

例子：Which would you single out as the best? 你觉得哪一个最好？

pick out 有多个意思。

1. 挑选出。

2. 分辨出。

3. 凭记忆奏出乐曲。

4. 细心研究后发现或领会某事物。