The flowers his friends gave him will die if every day.
A. not watering
B. not watered
C. not to water
D. not being watered
网友回答
A. not watering
(答案→)B. not watered
C. not to water
D. not being watered
解析：考查状语从句的省略。补充完整是The flowers his friends gave him will die if they are not watered every day.因为从句主语和主句主语一致，并含有be动词，可把从句的主语和 be省略。所以选B。