VOA慢速英语:Scientists Predict a Bad Year for the Monarch Butterfly

例句：He observes carefully but says little.
      他总是仔细观察, 很少说话。

vt.看到; 注意到

例句：Didn't you observe the difference?
      难道你没有看出差别?

2.magnetic adj.有磁性的, 有吸引力的

例句：She is magnetic.
      她很有吸引力。

      The iron has lost its magnetic force.
      这块铁已失去了磁力。

3.dispute vt.vi.辩论; 争论

例句：Some husbands and wives are always disputing.
      有些夫妇总是争吵。

      Let's dispute the decision.
      咱们来讨论一下这个决定吧。

4.violate vt.违反, 违背

例句：The country violates the international agreements.
      那个国家违背了国际协议。

5.appoint vt.任命, 委派
 
例句：He was appointed secretary.
      他被任命为秘书。

确定, 指定; 约定

例句：We must appoint a day to meet again.
      我们要约定好下次会面的日期。

6.questionable adj.可疑的;有疑问的

例句：Your argument is based on a set of questionable assumptions.
       你的论证建立在一套有问题的假设上。

      Their motives for undertaking this study are highly questionable.
      他们承担这项研究的动机大有问题。