12. I like getting up very early in summer. The morning air is so good______.（2008全国卷1）
A. to be breathed B. to breathe C. breathing D. being breathed
13. He was busy writing a story, only ______ once in a while to smoke a cigarette. [2008辽宁卷]
A. to stop B. stopping C. to have slopped D. having stopped
14. Please remain______; the winner of the prize will be announced soon. [2008辽宁卷B]
A. seating B. seated C. to seat D. to be seated
