已知正四面体ABCD的棱长为 $\sqrt{2}$ ，则其外接球的体积为（   ）

补写出下列名篇名句的空缺部分。

①引以为流觞曲水，列坐其次，____，____，亦足以畅叙幽情。(王羲之《兰亭集序》)

②歌台暖响，____ ；舞殿冷袖，____。(杜牧《阿房宫赋》)

③转轴拨弦三两声，____。弦弦掩抑声声思，____。(白居易《琵琶行》)

④醉里挑灯看剑，梦回吹角连营。____，____沙场秋点兵。(辛弃疾《破阵子》)

    ①The Internet is becoming more and more popular. It brings us a lot of fun and convenience, ②但它也引起一些新的问题。 Children like the Internet. They would rather communicate with others online than talk with their parents.

    On the one hand, in my opinion, the Internet brings people closer. On the other hand, ③如果我们花太多的时间在网络上, we will have less time with our families and friends in the real world.

    ④Parents are always staying with us. So why not talk to them face to face when we have problems. If so, ⑤I'm sure that we can get on well with our parents.