题目

Kid Inventors—Attend Kids' Day at the Invention ShowINPEX®, the American largest invention trade show, is looking for kid inventors to bring their inventions to Kids' Day at the Invention Show. Young inventors come for a chance to win cash prizes and great giveaways (赠品)．No invention? No problem！Kids' Day isn't just for kid inventors. Enjoy music, games and many interesting activities for all ages. Bring your family and friends for a fun day of creativity and excitement.Attention, young inventors!There will be lots of exciting activities to take part in and inventions to check out f欲探究铁、铜、银三种金属的活动性顺序，应选用比较恰当的试剂为 A、Fe  CuSO4溶液  Ag       B、FeSO4溶液  Cu   AgC、Fe  盐酸  Cu  Ag        D、 ．