66. Not only can walking fish live out of water, but they can also travel short distances over land.


  67. Scientists do not know why dinosaurs became extinct, but some theories postulate that changers in geography, climate, and sea levels were responsible.


  68. The science of horticulture, in which the primary concerns are maximum yield and superior quality, utilizes inFORMation derived from other sciences.


  69. Snow aids farmers by keeping heart in the lower ground levels, thereby saving the seeds from freezing.


  70. Even though the precise qualities of hero in literary words may vary over time, the basic exemplary function of the hero seems to remain constant.


巧背英语四级100个句子单词[12]: http://insuns.com/article/17793-1.html