题目

阅读下面短文，按照句子结构的语法情况和上下文连贯的要求，在空格处填入一个适当的词或者用括号中词语的正确形式填空。 Jane's grandparents have got abig farm. They live on the farm. Jane often goes to see her grandparents onweekends. On the farm there(be)many kinds of animals, like cows, dogs, chickens and ducks. Jane likes(play) with them because they can makeher happy. There islittle elephant on the farm. It isthin and small. It has no mother. It never playsother animals. It often walks aroundalone. Jane(love) it so much.She often gives the 将NaCl溶液滴在一块光亮清洁的铁板表面上，一段时间后发现液滴覆盖的圆周中心区(a)已被腐蚀而变暗，在液滴外沿形成棕色铁锈环(b)，如图所示。导致该现象的主要原因是液滴下面的氧气含量比液滴边缘少。下列说法正确的是A.（a）区腐蚀比（b）区腐蚀严重B.该过程发生了化学反应：4Fe＋3O2=2Fe2O3C.该过程是析氢腐蚀，负极反应为：Fe－2e－ =Fe2+D.该过程为吸氧腐蚀，正极反应为：O2＋2H2O＋4e－=4OH－