问题
选择题
The flowers his friend gave him will die unless _________ every day.
A．watering
B．watered
C．is watered
D．waters
答案
答案：B
题目分析：考查省略形式。unless后面应该加的完整部分是they are watered，前后主语一致都是flowers，这时可以省掉主语和be动词，这样只剩下watered。所以选B。