1) He doesn' t know the difference between right and wrong.

他不懂是非.
2) Small children do not know right from wrong.

小孩子不懂是非。
3) He couldn't distinguish right from wrong.

他是非不分。
4) What does lacking in understanding mean?

什么是不懂?
6) He has seen little of life.

他不懂世故。
补充资料:小孩子
1.见"小孩"。
说明:补充资料仅用于学习参考,请勿用于其它任何用途。
参考词条