It is impossible for us to finish _____(build) the new school in such a short time.

It is impossible for us to finish _____(build) the new school in such a short time.
It is impossible for us to finish _____(build) the new school in such a short time.

It is impossible for us to finish _____(build) the new school in such a short time.
building
finish doing sth 完成做某事.

building ,finish +doing 的形式

building
finish doing sth.

finish + doing sth.
所以本题填 building。
impossible for sb to + do sth. 这里的do就是finish.