rd the voices, but I couldn’t _______ what they were saying.

________ the calculation is right, scientists can never be sure that they have included all variables and modeled them accurately

(2017·北京)Many airlines now allow passengers to print their boarding passes online ________ their valuable time.

The number of students in this college _____ by 10% every year.

He’s never been to Canada, _______ he -_______. It’s his second time to be there.