21.Look over there—there’s a very long, winding path up to the lonely house.
A. leading B. leads C. led D. to lead
22.The schoolhouse________ now will be our library in 2014.
A. built B. building C .to be built D. being built
23.That is the only way we can imagine the overuse of water in students’ bathrooms.
A. reducing B. to reduce C. reduced D. reduce