They have made medicine from a new plant a cure for fever.A. used it asB. using asC. and u

问题补充：

They have made medicine from a new plant a cure for fever.

A. used it as

B. using as

C. and used as

D. used as

答案：

A. used it as

B. using as

C. and used as

(答案→)D. used as

解析：考查过去分词做定语，medicine和use是被动关系，用过去分词做定语，句意：我们从一种新的植物中研发了一种治疗感冒的药物。选D。