The flowers his friend gave him will die unless every day.
A. water
B. watering
C. watered
D. to water
网友回答
A. water
B. watering
(答案→)C. watered
D. to water
解析：
试题分析:考查非谓语。从结构判断此处是连词+分词形式做状语，动词water和主语flowers之间是被动关系，所以用过去分词。故C选项正确。句意：如果不是每天浇水的话他朋友给他的花就会死了。