BCBB
1.推理题:从文章第一段的In the 19th century, Americans from the eastern states moved out west to settle in the rich new lands along the Pacific Coast.可知他们是想在西部安家.选 B
2.推理题:从文章第二段的句子:The western desert can be very dangerous. There is little water and there are few trees. But the desert also has scenery of great beauty.说明答案是 C
3.从第四段的句子:In the 1800s, many travelers died when they tried to cross this waterless valley in the terrible heat.可知他们因为酷热而死.答案是B
4.细节题:从最后一段的句子:Snakes and rats have learned how to live in the desert heat. They live underground and come out at night, when it is cool.看出如果不会打洞,动物就会死.选B