For members of the seventeenth-century Ashanti nation in Africa, animal-hide shields with wooden frames were essential items of military equipment, a method to protect warriors against enemy arrows and spears.
30. For members of the seventeenth-century Ashanti nation in Africa, animal-hide shields with wooden frames were essential items of military equipment, a method to protect warriors against enemy arrows and spears. (A) a method to protect (B) as a method protecting (C) protecting (D) as a protection of (E) to protect
划线部分是用来修饰前面items of military equipment(中心词是items)表目的。 A items 不是a method(方法)。此外,items是复数,a method是单数。 B items是复数,a method是单数。as...开头有问题。 D名词形式很多都是wordiness E 不定式to protect不能修饰名词表目的,通常都是修饰动词表目的。