关于力和运动的关系，下列说法正确的是（　　）

鱼必须生活在水里，离开水一段时间就会死亡．对此最恰当的解释是（  ）

下列各组词语中读音和书写有错误的一项是（   ）

根据所给词的适当形式、音标或语境的提示，完成短文。

      Watertown is a great place for a family to take a vacation. Teenagers want to visit the world's ____ (large) water slides and eat at the Uncle Bob's. A different rock band ____ (play) at Uncle Bob's every night. Kids will enjoy the Clown City Café. They have organized games and the staff dress up  ____ (æz)clowns(小丑).

      There is also a lot for parents in Watertown. ____ (if) they love good food, they can find it at the Farmer's Market where the food is both ____ dɪ'lɪʃəs and cheap. While the children have fun, parents can take dance lessons on the beach. And ____ ('evribɒdi) can learn something in Watertown. There are three ____ (museum). Teenagers love the Sports Museum and kids enjoy the Science Museum. Parents will spend many hours ____ (walk) through the History Museum.

图（1）是一个长为2m，宽为2n（m＞n）的长方形，用剪刀沿图中虚线（对称轴）剪开，把它分成四块形状和大小都一样的小长方形，然后按图（2）那样拼成一个正方形，则中间空的部分的面积是