一、单项选择(30分)
从每小题A、B、C、D中选出一个能填入句中空白处的最佳答案。
1. （2012·泰安中考）The population problem may be _____ one of the world today.
A. the most B. most difficult
C. the greatest D. more interesting
2. —Is this your pen, Sam?
—No, it’s Peter’s. _____ is in my pencil case.
A. My B. Mine C. He’s D. His
