选择适当的单词, 完成短文。
cooked, was, goes, visited, washed, cleaned, stayed, drank
My mother ____busy last weekend. She usually ____to the park on weekends. But last weekend she ____at home. She ____the clothes and ____ our house, then she ____my grandparents on Sunday after-noon .They ____ tea together. My mother ____a big dinner for my grandparents. How happy they were!
人体内二氧化碳浓度最高的地方是（ ）
