对于某些常见离子的检验及结论一定正确的是 A.加入稀盐酸产生无色气体,将气体通入澄清石灰水中,溶液变浑浊,一定有CO32-B.加入氯化钡溶液有白色沉淀产生,再加盐酸沉淀不消失,一定有SO42-C.加入氯化钠溶液有白色沉淀产生,再加稀硝酸沉淀不消失,一定有Ag+D.加入碳酸钠溶液产生白色沉淀,再加盐酸白色沉淀消失,一定有Ba2+ The good scores of exams a
right attitude of study. If one has a right attitude of study, he good
results.
A. focus on, will get
B. are based on,will achieve
C. establish , receives