About 87.5％of the Chinese people feel that their living burdens are heavier than ten years ago, but their incomes ________．

1. A.
   have increased
2. B.
   increase
3. C.
   increased
4. D.
   had increased

（2010·江苏如东高级中学高三国庆假期自主练习一） 23. About 87.5% of the Chinese people feel that their living burdens are heavier than ten years ago, but their incomes ________.

A. have increased    B. increase       

C. increased            D. are increasing