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.
例:OG10-39 For members of the seventeenth-centuryAshanti nation in Africa, animal-hide shields with wooden frames were essentialitems of military equipment, a method to protect warriors against enemyarrows and spears.
A. a method to protect
B. as a method protecting
C. protecting
D. as a protection of
E. to protect
答案C。
OG关于D的解释不懂:D。Beginningthe phrase with as is incorrect; using the noun form protection createswordiness 。 as作介词用表示作为不可以么?