质量分数不同的硫酸溶液其密度不相同.对照表如下: 质量分数 10% 20% 30% 40% 50% 60% 70% 80% 90% 98% 密度 1.07 1.14 1.22 1.30 1.40 1.50 1.61 1.73 1.81 1.84 将10mL98%浓硫酸中加水稀释至100ml,取10mL该稀硫酸与足量锌反应制取氢气.请按要求完成系列问题的解答: (1)10mL98%的浓硫酸中含18 gH2SO4. (2)列式计算消耗金属锌的质量. 解:设10mL稀硫酸与锌完全反应消耗锌的质量为x. Zn+H2SO4=ZnSO4+H2↑ 65 98 X 18.0g× 答:略 (3)分析表中数据.可以归纳出硫酸溶液的质量分数与密度的关系是 质量分数越大密度越大 .10mL水和10mL质量分数为b%的硫酸溶液混合.混合后溶液的质量分数应该在 % 至 b% 之间. 查看更多

 

题目列表(包括答案和解析)

完型填空(共20小题;每小题1分,满分20分)
阅读下面短文,掌握其大意,然后从四个选项(A、B、C和D)中,选出最佳选项。
"Hey, Tahlia! How's the model?"
I had just taken a bite of my hot dog __21__ I heard a familiar voice yelling at me from across the crowded school yard. I saw a group of popular girls who were all __22__.
"What kind of __23_ are you going to do? An ad for a Frankenstein movie?" More laughter. My stomach twisted into a tight knot. How could they humiliate (羞辱) me like this, __24__ the entire school? As I walked into the cafeteria, I __25__ the dark scars on my right hand.
At 9 months old, I knocked over a tea pot and dumped boiling water allover my hands and stomach. My parents __26__ me to the hospital, but I had to have skin graft (移植) operation. I was in so much pain! But what __27__ me most were the cruel things people said about how I looked, __28__ that day at lunch.
The girls were being supermean to me because they'd heard I was considering doing some modeling. A close friend had suggested that I shouldn't let my scars limit me and that I might __29__ a good model.
But after that __30__ at school, I was sure I'd made a huge mistake. Upon arriving home, I covered the mirror with a blanket, fell on my bed and sobbed.
The next day, I __31__ myself to go to school. At lunch my best friend Jesse tried to encourage me: "You can't __32_ forever, Tahlia. So what if you have a few scars? Just go outside and show them that you're just as good as they are." Although I knew he was right, I couldn’t __33__ standing up for myself like that.
However, that night as I sat on the bed, my friend's words replayed in my mind. I'm __34__ hiding from myself, I thought. How stupid! Slowly, I stood up, walked over to the __35__, and tossed the blanket aside. There, in the mirror I saw a slim, dark-haired, blue-eyed girl, looking just fine, __36__ with a few scars.
The next day I wore a comfortable T-shirt to school. What's more, I had lunch outside the cafeteria, __37__ beside those mean girls. They were shocked that I should dare to walk into their territory. I felt __38_ too—free and happy.
Sometimes people still look at me strangely. They __39_ and stare, but I don't let it get to me. I have applied to several modeling companies, and at least one company is considering me for jobs. Maybe I'll never __40_ posing on the runway, but I do know one thing: I'm done.
【小题1】
A.as B.when C.while D.before
【小题2】
A.applauding B.cheering C.laughing D.quarreling
【小题3】
A.modeling B.writing C.drilling D.acting
【小题4】
A.in spite of B.in view of C.in terms of D.in front of
【小题5】
A.looked into B.searched for C.wondered aboutD.glanced at
【小题6】
A.presented B.sent C.rushedD.handed
【小题7】
A.hurtB.beat C.disappointed D.puzzled
【小题8】
A.for B.like C.on D.after
【小题9】
A.impressB.make C.consult D.defeat
【小题10】
A.effect B.phenomenon C.challenge D.scene
【小题11】
A.forced B.expected C.reminded D.preferred
【小题12】
A.apologize B.beg C.hide D.complain
【小题13】
A.consider B.imagine C.appreciate D.resist
【小题14】
A.hardly B.ever C.even D.gradually
【小题15】
A.blanket B.bed C.chair D.mirror
【小题16】
A.while B.though C.but D.because
【小题17】
A.right B.still C.therefore D.anyhow
【小题18】
A.sensitive B.uncomfortable C.different D.tense
【小题19】
A.compare B.associate C.wave D.whisper
【小题20】
A.give up B.end up C.put up D.set up

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