After years’ study with the help of Professor Henry Higgins, Eliza was able to________various levels of English usages, such as standard and substandard.

Please ________ it up and you’ll succeed ________.

27. If we ________ to him, he will make further demands.

--Peter! Hurry up! You ___ on the phone. ---Oh, I ___ .Thank you.

The water and soil conservation project resulted in farmers ______ the crops on the farmland  _____ trees and grass.