山西自考《英语（二）》复习资料--Text-Black Holes 2

词汇精讲：
　　1 escape v.逃跑，避免
　　A lion has escaped from its cage.
　　一头狮子从笼子里跑出来了
　　2 exert: vt.用尽；尽力；运用；行使；施加，产生（影响等）
　　用法：exert pressure on sb.给…施加压力
　　She exerted herself all year to earn good marks.她整年努力以期获得好分数。
　　He's been exerting a lot of pressure on me to change my mind.他一直在施加种种压力要我改变主意。
　　Black holes exert very strong gravity.黑洞产生很强的引力。
　　3 explode v.爆炸，突发
　　explosion n.
　　explosive a.
　　A bomb exploded at one of London's busiest railway station this morning.
　　今天上午一颗炸弹在伦敦最繁忙的火车站爆炸了。
　　4 collapse v.n.倒塌, 崩溃
　　例句 参考教材第34-35页的 word Study 2
　　5 shrink: (shrank, shrunk ) v.退缩；畏缩；n.收缩；缩小
　　用法： The gross national product shrank one percent last year.去年国民生产总值减少了1%。
　　Washing wool in hot water will shrink it .在热水中洗羊毛会使它缩水。
　　We will never shrink back before difficulties .我们在困难面前决不退缩。
　　6 boundary n.分界线，边界
　　We crossed the state boundary at midnight.
　　我们在午夜穿过了州界。
　　7 constant adj.不断的，经常的；永恒的，始终如一 n..常数
　　He is in constant trouble with the police.他总是不断和警察惹麻烦。
　　There are no constants at all.根本没有不变的事物。