who is the man () is watering the flowers over there whom that where which

问题描述:

who is the man () is watering the flowers over there whom that where which
who is the man () is watering the flowers over there
whom that where which
选择哪一个?
还有我不是很明白那些定语从句还有它的关系代词.

that做主语
其他不能做主语