Question

That is the only way we can imagine ________ (reduce) the overuse of water in students' bathrooms.

Answer 1

to reduce　

受插入语we can imagine的干扰，考生很容易误填reducing。去掉插入成分可以看出，后面的to reduce the overuse of water in students' bathrooms是定语，修饰中心词way。way后的定语有两种：a way of doing sth.或者a way to do sth.。