He started to study ecology and decided to _______his whole life to the science.

as the professor’s lecture—Impressive Thank you so much for giving me a lift during the rushhours If not, I ________ the lecture today

Every time the class teacher walks past the window, the two boys pretend _________ closely.

why didn’t you come yesterday—I __________, but I had an unexpectedvisitor

_______ matters most in learning English is enough practice.