题目

Thank you for offering me _____.      A. so many valuable suggestions     B. so much valuable suggestion       C. so many valuable advices  D. so much valuable advices 答案：A下列反应中，属于氧化还原反应的是（ ）A．Na2CO3+2HCl=2NaCl+H2O+CO2↑B．SO3+H2O=H2SO4C．4HCl（浓）+MnO2MnCl2+Cl2↑+2H2OD．CaCO3CaO+CO2↑