题目

 During the last three decades, the number of people participating in physical fitness programs _____ sharply. A. was increasing    B. has increased   C. had increased      D. will be increasing 答案：B用氯化钠和水配制150g 16%的氯化钠溶液，正确的操作顺序是（　　）A．计算、称量、量取、溶解B．称量、计算、量取、溶解C．量取、称量、溶解、计算D．计算、量取、溶解、称量