转化器混合气流量提不上来是因为()。 ["原料气压力不足","原料气纯度低","已炔量低","触媒失去活性"]
手工干洗剂有四氯乙烯、酒精还有() ["A、肥皂","B、汽油","C、洗衣粉","D、柔软剂"]
环氧乙烷贮罐在氮气压力为0.2MPa(A)时环氧乙烷在()℃以下是安全的。 ["A、<47℃","B、<37℃","C、<27℃","D、<17℃"]
原子晶体解离时,遵循的原则有()。 ["解离时断裂的是离子键","断裂的是共价键,其极性较强","解离面破坏原子团","解离面不破坏原子团","解离面只分裂了分子,没有分裂原子"]
环氧乙烷贮罐在氮气压力为0.3MPa(A)时环氧乙烷在()以下是安全的。 ["A、<45℃","B、<35℃","C、<25℃","D、<15℃"]
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