It's Sunday. Wei Fang and Meimei are on their 1 to the zoo. They are waiting for a 2at the bus stop. Wei Fang 3something on the ground. She picks 4up. Oh, it is a new watch. “5 is it?” They 6the people at the bus stop. But they don't know. “ Let's wait for the owner.” Meimei 7. They wait and wait, but the owner 8come. So they have to give 9to a policeman nearby. The policeman says, “10 good girls you are!”

2012年诺贝尔化学奖颁发给了美国科学家罗伯特•约瑟夫•莱夫科维茨（Robert Joseph  Leflcowitz）和布莱恩•肯特•科比尔卡（Brian Kent Kobitka），以表彰他们哪方面的研究贡献（　　）

己知：2MnO₄^﹣+5H₂O₂+6H⁺═2Mn²⁺+8H₂O+5O₂

操作①：取10.00mLH₂O₂溶液（密度为1.00g•mL^﹣1）置于锥形瓶中加水稀释，再加稀硫酸酸化；

操作②：用0.200 0mol•L^﹣1KMnO₄溶液滴定；

操作③：用同样方法滴定，4次消耗KMnO₄溶液的体积分别为20.00mL、19.98mL、20.02mL、22.00mL．请回答下列问题：