题目

 —I wonder ______ Tina will come to my birthday party. —She is sure to come if she ______ time.              A. if; has                              B. that; will have                    C. when; has                        D. whether; will have   答案：A20．将CO2气体通入下列溶液中，无明显现象的是（　　）A．NaAlO2溶液B．Na2SiO3溶液C．漂白粉溶液D．CaCl2