没有区别。bit是bite的过去式，动词为咬的意思。bite 名词为咬伤，动词为咬。例：She was bitten by the family dog.(她被家里的狗咬伤了)
bite：v.咬;叮;蜇;咬饵;上钩；n.咬;(咬下的)一口;小量食物;简单的一餐
相关介绍
例句：
Wind forward to the bit where they discover the body.
往前绕片，绕到他们发现尸体的那一截。
Can you turn the volume up a little bit?
你能把音量开大点儿吗？
Actually, I'll be a bit late home.
说真的，我回家会晚一点。
We can finish this job on time if everyone does their bit.
要是每个人都尽职，我们就能按时完成这项工作。
