题干

沼气(主要成分是甲烷)是当今开发的洁净能源之一,是解决农村能源不足问题的重要途径.

①写出甲烷燃烧的化学方程式:____

②沼气中除含有甲烷外,还含有二氧化碳及少量的氢气、氮气、硫化氢、一氧化碳、水蒸气等.沼气略带臭味,你认为臭味可能来自____气体.平时在我们家用的液化石油气中也加入少量带臭味的气体,其目的是____

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答案(点此获取答案解析)

CH4+2O2 \u70b9\u71c3_

同类题4

选择合适的选项补全短文。

Ways to Worry Less

    Do you want to worry less? Of course you do,fight? That's like me asking if I could send you free bacon.Worry is like black mold—it appears in damp conditions and spreads uncontrollably.And often times we don't realize it's there until it's killing us.We must get rid of worry before it destroys us.But how?____

    Do what you need to do.

    ____You ought not to avoid tough projects or hard conversions until the last moment.If you don't do what you should be doing,you will end up spending the rest of the time worried about the must-to-do things.Believe it or not, the anxiety that comes from worrying is much worse than the task we're worried about.____

    I think many of us act like we're puppets(木偶)in a play and we're waiting for something or someone to put us in the right place.You just react to whatever is going on.____We need to live on purpose.Nothing can cause worry like purposelessness.

    Make plans.

    You can't have intentionality without making plans.Making plan will enable you to achieve your aims more smoothly.Yet,don't place your plans in stone.You can adjust your plans flexibly.Accept changes.____

    There are other ways to lessen worry.As long as you are determined to take action,you will live a worry-free life.

A.Worry ruins creativity.

B.Get more intentional.

C.Do what you should be doing.

D.We need to stop letting life just happen.

E.Make new plans and then move forward.

F.You do the same as people around you do.

G.Here are some effective ways to deal with it.