试题题干
Word Formation
Complete the following sentence with the proper form of the word in the bracket.
(treat) First aid is emergency care for a victim of sudden illness or injury until more skillful medical 
is available.
参考答案
试题解析
此处缺少名词。
is是系动词，空格处应该作主语，一般是名词作主语。所以变treat为名词treatment。
句意：急救是在突发疾病或突然受伤的患者在得不到更有经验的治疗时使用的。