题目

未来10年，有望成为我国石油生产龙头的是（ ）    A． 新疆                 B． 山东                        C． 西藏                       D． 大庆 答案：A．  Mary used to _________ to work, but she is used to ________to work now.A. riding a bike, taking a bus B. riding a bike, take a busC. ride a bike, taking a bus D. ride a bike, take a bus