在数列$\left\{a_n\right\}$中，$a_1=2$， $a_{n+1}=a_n+\ln (1+\frac{1}{n})$，则$a_{n=}$ （   ）

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①夜晚的都____（dū  dōu）市，大大小小的街道都____（dū  dōu）亮起了灯光。

②农民正在开心地____（dì  de）采摘地____（dì  dｅ）里的萝卜呢。

③你还____（hái  huán）有一本书没有还____（hái  huán）给我。

④我____（己  已）经是一年级的小学生了。

⑤放学了，小甜____（在  再）教室打扫卫生，同学们跟她说____（在  再）见。

⑥听到这个消息，小明____（经常  非常）开心。

⑦科学家____（发明  发现）了许多高科技的产品，改变了人们的生活。

⑧橱（chú）窗里摆着____（各种各样  许许多多）的商品。

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.

香港和澳门都非常发达的部门是（    ）