计算：(-2)+1的结果是（   ）

“三角”    表示3abc，“方框”   表示﹣4x^yw^z，则   =____ ．

已知两圆半径$r_1$、$r_2$分别是方程$x^2-7x+10=0$的两根，两圆的圆心距为7，则两圆的位置关系是（    ）

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。

Journey to the Center of the Earth spoke of a trip to the centre of the earth through a volcano in Iceland. When Professor Otto Lindenbrock，his nephew and the guide they hired ____(reach) the volcano， they journeyed underground through a small cave. After many days， they came to a vast room ____a large ocean inside. The three men built a small boat and set sail.____ (sudden)， two dinosaurs rose to the surface and began to fight each other. The small boat was almost sunk by the dinosaurs ____they were able to get away.

They sailed to shore and explored the forest. They came across huge insects and many strange ____(creature). As they were wandering around， they noticed a man sitting against a tree in the ____(distant)—he was at least four meters tall. The men became afraid， and ran back to the boat.

The boat floated down with the water ____ they could only hold on to the boat in terror. Finally， they reached the bottom of the hole. Then the water began to push them up. They floated upwards for miles. The water rushed beneath them， ____(push) them out into the sunlight. They now found ____(they) in a volcano in Italy—their adventure was over，but a new one was about ____(begin).