题干

下列图示与对应的叙述相符的是(   )

A: 表示常温下盐酸滴加到0.1mol/L某强碱溶液得到的滴定曲线

B: 表示一定条件下进行的反应2SO2+O2⇌2SO3各成分的物质的量变化,t2时刻改变的条件可能是缩小容器体积

C: 表示某明矾溶液中加入Ba(OH)2溶液,沉淀的质量与加入Ba(OH)2溶液体积的关系,在加入20mLBa(OH)2溶液时铝离子恰好沉淀完全

D: 表示pH相同的盐酸与醋酸中分别加入水后溶液pH的变化,其中曲线a对应的是盐酸

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答案(点此获取答案解析)

B

同类题2

    The world has many beautiful sounds. We can hear the songs of birds and the laugh of people. We can listen to the cool music and news reports. And it's all because of our ears! They bring us a world of sounds. But some people can't hear any sound at all. Some are born deaf. Others can hear well in their childhood, but too many loud sounds hurt their ears later on. Many people in China can't hear ordinary sounds clearly. A large number of them are children. Most of them are born with good hearing. But six children of every 1,000 have hearing problems when they are born. And if a child has hearing problems, he or she usually will also have some learning problems at school. A lot of things can cause hearing problems. For example, too much earwax is not good for our hearing. And noise louder than 85 decibels (分贝) can hurt our ears and make us lose our hearing for a short time or even for ever. Hearing is important for all of us. So we should do our best to give our ears special care. Don't forget to do the following:

● Try to stay away from places with too much noise. If you have to go, wear earplugs. A pair of good earplugs can cut the noise by 30 decibels. ● When swimming, remember to put earplugs into your ears to stop water from getting in.

● Never put anything sharp into your ears. If you think you have too much earwax, ask your mum or dad to help you clean it out. Keep these things in mind! Then you won't be saying “WHAT? WHAT?" when you are older.