问题补充：
Who for the pollution of our earth?
A. should blame
B. is to blame
C. is blame
D. is to be blame
答案：
A. should blame
(答案→)B. is to blame
C. is blame
D. is to be blame
解析：blame用作及物动词时,通常用于下面三个句型:
（1）. blame sb. for sth. /doing sth. 为某事责备某人/责备某人做了某事。如:
Many children are afraid of being blamed for making mistakes in speaking English.许多孩子害怕讲英语时犯错误而受责备。
（2）. blame sth. on sb. 把某事归咎于某人。如:
The police blamed the traffic accident on Jacks careless driving. 警察把那起交通事故归咎于杰克的粗心驾驶。
（3）. be to blame (for)应(为……)承担责任;该(为……)受责备。[注意]此处不能用被动语态。如:
The children were not to blame for the accident. 那次事故怪不着孩子们。
He is more to blame than you. 是他更应受责备,而不是你。
Who is to blame for starting the fire? 这场火灾该由谁负责?
I am in no way to blame.决不该责备我。
故选B。
