cause ①名词，起因、原因
【辨析】cause与reason
区别一
表示造成某一事实或现象的直接原因或起因，常用 cause of结构。如：
Carelessness is often the cause of fires. 疏忽大意往往酿成火灾。
区别二
若是说明或解释某种行为或看法的借口、理由，常用reason for，reason whythat结构。如：You have no reason for complaint. 你没有理由抱怨。
注：表示“理由”时，两者虽然常常互换，但也有区别：
(1) cause 是不可数名词，而 reason 可用作可数或不可数名词，因此当需要用复数或受 a, every, many 等修饰时，通常要用 reason 。如：
I have many reasons to fear him. 我怕他是有很多理由的。
(2) reason 之后可接 why 引导的定语从句，而 cause 不能。如：
The reason (why) I didn’t tell you was that I wanted it to be a surprise. 我没有告诉你，是想让它给你一个惊喜。
②动词，引起，导致
Many accidents are csused by careless driving.
【词组】cause she sth
cause sb/sth to follow sth
Chatting online may cause you much trouble. 网上聊天可能给你带来很多麻烦。
What caused the ship to sink?是什么导致了船的沉没？
【小试牛刀】
Many accidents ________ by careless drivers last year.
A. are caused
B. were caused
C. have caused
解析：选B
