题目

阅读下面短文，从短文后各题所给的四个选项A、B、C和D中，选出可以填入空 白处的最佳选项。On his knees, a cute boy ispacking the sand into a bucket at a beautiful beach. He turns the bucket upsidedown and 1 it. To the 2 of the little architect, a castle tower iscreated. He works all afternoon packing the walls, building sentries (哨兵) with bottle tops andbridges with sticks. And a sandcastle will be built.In a big city with 3 streets and traffic, a man is working in anoffice. He packs papers into piles, holds the phone between his 4 and shoulder and 5 the 如果把细胞搅碎，细胞将死亡；病毒不具有细胞结构，如果把病毒搅碎，病毒也将失去活性，这说明（ ）A.细胞和病毒的结构相似B.细胞和病毒失活是因为破坏了它们的化学成分C.两者的功能都与其结构的完整性密切相关D.单细胞生物和病毒对环境的适应性很差