a bit of = a little 一点(修饰不可数名词)
eg. Who can give me a bit of advice of making a paper flower?
The cat drank a bit of water and walked away.
a bit= a little一点（修饰形容词或副词）
eg.I'm a bit slow in the mind now after working for four hours without a break.
It was a bit rude of you not answering his question directly.
bits of 小块的,碎片
dg. There are bits of broken glass on the floor because the cat knocked down a bottle.
另外补充一下：
not a bit=not...at all 修饰形容词：一点也不
not a little=very 修饰形容词：非常
eg.He's not a bit hungry but not a little tired.他一点也不饿,但非常累
希望我的回答对您有帮助O(∩_∩)O
再问： a bit of与a bit一样吗？
再答： 不一样，a bit of 修饰不可数名词 a bit 修饰形容词和副词。
