21. Leaves are found on all kinds of trees, but they differ greatly _____ size and shape.
A. on B. from C. by D. in
【解析】选D。与……不同，用from；在……方面不同, 用in。
22. People in America speak the same language _____ the British do.
A. which B. what C. as D. like
【解析】选C。the same as 与……一样。
