A:NO中含有NO2,用水洗涤后再干燥
B:CO2中含有SO2,通入饱和NaHCO3溶液后干燥
C:NH3中含有H2O,用CaCl2进行干燥
D:SO2中含有HCl,通入饱和NaHSO3溶液后干燥
—Good idea. I think ____ the general manager ___ the chief engineer have the courage to take on the challenge.
下面对郑和下西洋的原因上说法正确的是( )
①宣扬国威 ②到西洋去“取宝” ③为开辟新航路 ④加强同海外各国联系