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代表秦汉雕塑艺术水平，有“世界第八大奇迹”之称的是什么（     ）

操作显微镜下调镜筒时，眼睛一定要看着（  ）

阅读理解

    What is the first thing you want to do when you see someone yawn? You want to yawn, too! Yawning is contagious.
    Scientists have found that all people yawn. Babies start to yawn even before they are born. The earliest yawn takes place when a baby is still inside its mother. When young children are about one year old, they start to yawn when they see others yawning. That's why scientists think yawning is contagious.
    It's no secret that yawning is contagious, but why do we yawn? Well, scientists are not really sure.
    Some think we yawn because we feel bored. Others believe yawning has something to do with breathing. When there is too much carbon dioxide(CO₂) in our bodies, our bodies will tell the brains to breathe deeply. That causes a big yawn.
    In 2007, scientists said people yawned to cool down their brains. These scientists found people yawned more often if they were warmer than others.
    Scientists are still trying to find out why yawning happens and why it is so contagious. But they are only sure that when one person yawns, immediately everyone else nearby wants to yawn, too.

一个等腰直角三角形和一个正方形如图摆放，被分割成了5个部分． ①，②，③这三块的面积比依次为1：4：41，那么④，⑤这两块的面积比是____