题目

—What is your plan for the holiday, Paul? —I’ll go on a trip to Yunnan Province with my family.    —_____. A. Have a nice time              B. Good luck C. Come back soon        D. Congratulations 答案：A 解析: 略某盐的混合物中含有0.2 mol／L Na+、0.4 mol／L Mg2+、0.4 mol／L Clˉ，则SO42ˉ为 A．0.1 mol／LB．0.2 mol／LC．0.3 mol／LD．0.4 mol／L