1/5单选题
难度：
1.能使带火星的木条复燃的气体是
| A | 氧气 |
| B | 稀有气体 |
| C | 氮气 |
| D | 二氧化碳 |
- 提示1：
- 5rCn5rCU5YW35pyJ5Yqp54eD5oCn44CC
正确答案：QQ==
5rCn5rCU6IO95aSf5pSv5oyB54eD54On77yM6IO95L2/5bim54Gr5pif55qE5pyo5p2h5aSN54eD77yOPGJyPuetlOahiO+8mkHjgII=
2/5单选题
难度：
2.下列关于氧气的性质描述，错误的是
| A | 氧气极易溶解于水，使水中生物能生存 |
| B | 氧气的密度比空气略大 |
| C | 氧气是一种化学性质比较活泼的气体 |
| D | 液氧是一种淡蓝色的液体 |
- 提示1：
- 5qC55o2u5rCn5rCU55qE54mp55CG5oCn6LSo44CB5YyW5a2m5oCn6LSo44CB55So6YCU562J5pa56Z2i6L+b6KGM5YiG5p6Q5Yik5pat5Y2z5Y+v77yO
正确答案：QQ==
QeOAgeawp+awlOS4jeaYk+a6tuino+S6juawtO+8jOWcqOawtOS4rea6tuacieWwkemHj+eahOawp+awlO+8jOS9v+awtOS4reeUn+eJqeiDveeUn+WtmO+8juaVhUHplJnor6/vvJs8YnI+QuOAgeawp+awlOeahOWvhuW6puavlOepuuawlOeVpeWkp++8juaVhULmraPnoa7vvJs8YnI+Q+OAgeawp+awlOaYr+S4gOenjeWMluWtpuaAp+i0qOavlOi+g+a0u+azvOeahOawlOS9k++8juaVhUPmraPnoa7vvJs8YnI+ROOAgea2suawp+aYr+S4gOenjea3oeiTneiJsueahOa2suS9k++8juaVhUTmraPnoa7vvI48YnI+5pWF6YCJQe+8jg==
3/5单选题
难度：
3.氧气是空气的主要成分之一，下列有关氧气的说法错误的是
| A | 通常状况下是无色无味气体 |
| B | 用带火星的木条可以检验氧气 |
| C | 鱼类能在水中生存，证明氧气易溶于水 |
| D | 通常状况下密度略大于空气的密度 |
- 提示1：
- MUzmsLTkuK3lpKfnuqbog73lpJ/murbop6MzMG1M5rCn5rCU44CC
正确答案：Qw==
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
4/5单选题
难度：
4.做铁丝在氧气中燃烧的实验时，要先点燃铁丝上系着的火柴，再伸入集气瓶中，火柴燃烧的作用是
| A | 补充氧气 |
| B | 增加可燃物 |
| C | 降低细铁丝的温度 |
| D | 升高细铁丝的温度 |
- 提示1：
- 54Gr5p+054eD54On5pe25pS+5Ye655qE54Ot6YeP77yM57uZ6ZOB5Lid6aKE54Ot77yM5o+Q6auY6ZOB5Lid5rip5bqm77yM5Yip5LqO6ZOB5Lid54eD54On77yM54Gr5p+05p2G6LW35byV54eD5L2c55So77yO
正确答案：RA==
QeOAgeeBq+aftOeHg+eDp+a2iOiAl+S6huawp+awlO+8jOS4jeiDveihpeWFheawp+awlO+8juaVhUHplJnor6/vvJs8YnI+QuOAgeWinuWKoOWPr+eHg+eJqe+8jOa2iOiAl+S6huawp+awlO+8jOS4jeWIqeS6jumTgeS4neeahOeHg+eDp++8juaVhULplJnor6/vvJs8YnI+Q+OAgemTgeS4neeahOedgOeBq+eCueaYr+mTgeeahOWxnuaAp++8jOS4gOiIrOS4jeiDveaUueWPmO+8juaVhUPplJnor6/vvJs8YnI+ROOAgeeBq+aftOeHg+eDp+eahOS9nOeUqOaYr+WNh+mrmOe7humTgeS4neeahOa4qeW6pu+8jOWIqeS6jumTgeS4neeHg+eDp++8jOaVhUTmraPnoa7vvI48YnI+5pWF6YCJ77yaRO+8jg==
5/5单选题
难度：
5.下列物质在氧气中燃烧的装置不正确的是
| A |  |
| B |  |
| C |  |
| D |  |
- 提示1：
- 6ZOB5Lid54eD54On5Lya54Gr5pif5Zub5bCE77yM5pyJ6auY5rip54eD54On54mp55Sf5oiQ44CC
正确答案：QQ==
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