题型:选择题 Make sure to put dangerous things in the place which the children can't________.[ ]A. create B. approach C. defend D. preserve 查看答案
题型:选择题 在水溶液中能大量共存,且加入过量稀硫酸溶液时,有气体生成的是( )A.Na+Ag+ CO32-Cl-B.K+Ba2+ SO42- Cl-C.Na+ K+ CO32- Cl-D.Na+ K+ Cl-SO42— 查看答案