标志着二战以后美苏战时同盟关系正式破裂,双方之间冷战开始的是()
A、丘吉尔发表“铁幕”演说
B、杜鲁门提出杜鲁门主义
C、北约和华约的建立
D、古巴导弹危机
参考答案:B
根据各句中所给汉语注释,在句子右边的横线上写出其正确形式。
1. Can you ______ (组织) the games for the class party?
2. There are a lot of old ______ (工厂) in our city.
3. Be ______ (小心) of the dog that does not bark.
4. You have to be 18 years old before you are ______ (允许) to drive a car.
5. Everyone else in my class was invited ______ (除) me.
11.2L甲烷、乙烷、甲醛组成的混合气体,完全燃烧后生成15.68LCO2(气体体积均在标准状况下测定),混合气体中乙烷的体积百分含量为( )
A.20%
B.40%
C.60%
D.80%