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】復合句。主句主干為you can delete material and add material and make your paper convincing。 句首的once引導條件狀語從句；that引導的定語從句修飾其前的 material；形容詞短語 necessary to illustrate your points做后置定語修飾第二個material。

【譯文】一旦初稿寫成，你就可以刪除與文章主題無關的材料，添加需要的材料來證明你的觀點并使文章具有說服力。

臨摹答案

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.