题目

阅读理解，选择正确的答案。David’s grandparents live in a small town near Suzhou. They have a nice house. Last Sunday, David went to visit them with Su Hai, Su Yang, Gao Shan, Yang Ling, Liu Tao and Ben. David’s grandparents were very glad to see them. David’s grandpa showed them a lot of stamps from different countries, and his grandma cooked a nice meal for them. They all liked the meal very much.In the morning, David and his friends cleaned the house. After lunch, the children worked in the garden. Su Hai and Su Yang watered trees and flowers. David and Gao Shan picked app制作动物细胞临时装片时，为了维持细胞正常的形态，需要滴加的液体是（ ）A. 生理盐水 B. 医用酒精 C. 稀碘液 D. 蒸馏水