There are different 1of animals in the zoo. We can see the zoo keepers (饲养员) give them food to 2. They don't have to 3 food by themselves. They just eat, walk and sleep 4 day. So many of us think the animals in the zoo are 5 and lucky. But most of them are sad. Why? They are no longer free.

    Animals 6 elephants, monkeys and tigers usually live freely and happily 7 forests (森林) or mountains. Tigers, for 8, run, jump, play 9 their children and catch small animals for food. But now they have to stay in small cages in the zoo. Their life in the zoo is quite different from their life in the forests. Now many people think more animals should go 10 to forests and mountains so that they become free and happy again.

用同种材料制成的两个大小不同的实心球，A球质量是B球质量的4倍，那么可知（   ）

-- Judy's never been late for school,         she?

--         . She is always the first to get to school every morning.

如图所示，MN表示真空室中垂直于纸面放置的感光板，它的一侧有匀强磁场，磁场方向垂直于纸面向里，磁感应强度大小为B．一个电荷量为q的带电粒子从感光板上的狭缝O处以垂直于感光板的初速度v射入磁场区域，最后到达感光板上的P点．经测量P、O间的距离为l，不计带电粒子受到的重力．求：

中东地区最丰富和最缺乏的自然资源分别是（    ）