Black and white 黑白分明的
若说某个局面是 black and white, 那意思就黑白分明，很容易判别错与对。
I'm really sure about some things. I think free education for all is a black and white issue.
The question of nuclear power isn't black and white. Many people believe it is the only way to produce a large amount of clean energy - but many others think it has considerable dangers.
短语 in black and white 的意思是白纸黑字，常用来形容某事被写下来作记录。
I couldn't believe I had won the lottery, but when I checked my bank statement there it was in black and white: one million dollars!