P为椭圆$\frac{x^2}{25}+\frac{y^2}{16}=1$上一点,M、N分别是圆(x+3) ²+y²=4和(x-3) ²+y²=1上的点,则|PM|+|PN|的取值范围是 （　　）

“机械化生产取代古老的手工操作，大工厂把小作坊远远抛在后面，铁路与轮船取代马车和帆船。”这一巨变把人类带人到崭新的（    ）

阅读下列材料，回答问题。

材料一：2008年，冰岛大力发展铝生产，铝年产量达76万，成为世界铝生产大国之一，其产量占世界铝产量(1300-1400万吨)的50%。

材料二：冰岛金融业在2007年全球信贷危机中损失惨重，冰岛克明对欧元汇率缩水3成，外债超过1383亿美元，而其国内生产总值仅为193．7亿美元，冰岛面临“国家破产”危险。

材料三：鱼肝油是由深海海鱼、鲸或海豹等海洋生物肝脏炼制的油脂，常用于防治夜盲症、角膜软化、佝偻病和骨软化症等。世界上知名的鱼肝油产地是挪威、冰岛等北欧国家，尤以冰岛的鱼肝油品质最好。

材料四：冰岛多火山、河流，水力和地热资源得天独厚，右图为冰岛火山、河流与公路分布图。

阅读下面材料，在空白处填入适当的内容（1个单词）或括号内单词的正确形式。

    Once a farmer lost his watch in his barn, in which lots of grain was kept. The watch, ____ was a gift from his father, was very important to him and he was determined to find it.

    After searching the barn for a long time, however, he gave up and asked for help from a group of children who were playing nearby. He promised to give a great reward to ____ found the watch.

    ____ (hear) this, the children hurried inside the barn immediately . ____ searched everywhere but still could not find the watch buried in the grain. The farmer was about to give up ____ a little boy went up to him and asked to be given ____ second chance.

    The farmer looked at him and thought, “Why not? After all, this kid looks honest.”

    So the farmer sent the little boy back into the barn. After a while the little boy came out ____ the watch in his hand! The farmer, ____ (surprise) but happy, asked the boy how he succeeded where the rest had failed.

    The boy replied, “I did nothing but ____ (sit) quietly and listen for the sound of the watch.”

    This shows us that sometimes a peaceful mind can think ____ (well) than an excited one.