A:NH3(H2O含石蕊) 蓝色喷泉
B:HCl (H2O含石蕊)红色喷泉
C:C12(饱和食盐水) 无色喷泉
D:CO2(NaOH溶液) 无色喷泉
谈谈“行己有耻”“止于至善”的含义?
—______ can you finish your homework? —In about one and a half hours.