由碳原子构成的纳米碳管可以作为储存氢气的优良容器，其单层部分结构示意图如图，下列说法正确的是（　　）

《这才是晚清》中记述：“历史不因大清帝国的孤傲和拒绝改变进程，鸦片战争使中国遭遇千年未遇的大变局。”“大变局”是指（    ）

Hello, I’m Linda. I have four friends. They are Ann, Lisa, Tom and Peter. Ann lives near school. She comes to school on foot. There is an underground station near Lisa’s home. She comes to school by underground. Tom lives far from school. He comes to school by bus. Peter likes riding. He comes to school by bike.

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