Question

9. It's very hot here in summer. So the workers are required that        at least once a day. (water)

这儿的夏天太热了，所以工人们应该至少每天给花浇一次水。

Answer 1

9. they ( should) water the flowers动词require 后的宾语从句中的谓语动词部分应该用should do,should可以省略。