86. Artificial flowers are used for scientific as well as for decorative purposes. They are made from a variety of materials, such as way and glass, so skillfully that they can scarcely be distinguished from natural flowers.


  87. Three years of research at an abandoned coal mine in Argonne, Illinois, have resulted in findings that scientists believe can help reclaim thousands of mine disposal sites that scar the coal-rich regions of the United States.


  88. When the persuading and the planning for the western railroads had been completed, the task remained: the dangerous, sweaty, backbreaking, brawling business of actually building the lines.


  89. Because of the space crunch, the Art Museum has become increasingly cautious in considering acquisitions and donations of art, in some cases passing up opportunities to strengthen is collections.


  90. The United States Constitution requires that President be a natural-born citizen, thirty-five years of age or older, who has lived in the United States for a minimum of fourteen years.


巧背英语四级100个句子单词[16]: http://insuns.com/article/17793-1.html