某同学捉到一只活青蛙，把它放到有较多水的鱼缸中，并用玻璃板盖住，准备精心饲养，观察青蛙的活动， 可第二天青蛙就死掉了，青蛙死亡的原因最可能是（ ）

法国和德国的科学家费尔和格林贝格尔由于发现了巨磁电阻（GMR）效应，荣获了2007年诺贝尔物理学奖，如图所示的是研究巨磁电阻特性的电路示意图，当闭合S₁、S₂后，使滑片P向左滑动的过程中，指示灯明显变亮，则下列说法正确的是（　　）

完形填空。

    A boy and a girl catch a bird and 1 it in a birdcage (鸟笼）. They like it 2 and 3 it every day. A cat sees the bird and wants 4 her supper. 5 the bird is in the cage. She can't catch it. So she is very 6.

    One day, she opens the door of the cage 7 wants to catch it. But the bird flies away. The cat 8, and she has 9. The two children 10 and　see the bird isn't in. They are very angry and put the cat into the cage.