题目

 Everyone in the village is very friendly. It doesn’t matter ___ you have lived there for a short or a long time. A. why                        B. how                       C. whether                 D. When 答案：C下列物质名称对应的化学式正确的是（ ）A.氧化镁 MgOB.氢氧化钠 CaOHC.氯化锌 ZnClD.碳酸钠 NaCO3