_____ doing more exercise to lose weight, many teenagers would rather be a couch potato.
--- Would you mind if I used your bike? --- ____.
The president spoke at the business meeting for nearly an hour without ____ his notes.
David worked hard at his lessons ____ he gained high grades in the exams.
As a young man, Zhou Enlai ____ the students movements and later ____ the Communist Party of China.
Camels were ____ better than horses for travelling a long distance.