27.Once you have a first draft you, can delete material that is unrelated to your thesis and add material necessary to illustrate your points and make your paper convincing.

【分析】复合句。主句主干为you can delete material and add material and make your paper convincing。 句首的once引导条件状语从句；that引导的定语从句修饰其前的 material；形容词短语 necessary to illustrate your points做后置定语修饰第二个material。

【译文】一旦初稿写成，你就可以删除与文章主题无关的材料，添加需要的材料来证明你的观点并使文章具有说服力。

临摹答案

25.Heart cerebral sufferers should keep track of their diet and avoid oily or salty food.

26.A primary requirement for success in this area is to take advantage of the benefits of new technology and create a sound infrastructure that affords super efficiency.