276. Computer technology has _____ a revolution in business practices. Which of the following words is not suitable to be put in the blank?

I wonder what makes you a successful manager.—I _______as a waiter for five years and it makes a lot of contributions to my today’s work.

(2013·四川，9)Nowadays people are more concerned about the environment________they live.

The students ___ busily when Miss Brown went to get a book she ___in the office.

oat is smarter than mine, but mine is _________ cheaper thanyours