“兵匪互换”是北洋政府期间军队与土匪的非制度关系的主要表现。朱执信有云：“古人寓兵于农，近人寓兵于匪”；黎元洪总统1922年通电亦称：“遣之则兵散为匪，招之则匪聚为兵”。该现象的出现（    ）

根据课文内容选词填空。

             thick      soft        hot         hear       blind      elephant        hard

    It is a____ day. Four men are under a tree. They are all ____ . They cannot see. Then they ____  a noise. Oh, it's an____ . They touch the elephant. One touches its ear, he thinks the elephant is____ . One touches its tooth, he thinks it's ____ . One touches its tail, he thinks it's thin. One touches its leg, he thinks it's ____ . How funny!

下列光学中不正确的是（　　）