Although the living standards of Chinese people have greatly improved most poor families

问题补充：

Although the living standards of Chinese people have greatly improved, most poor families in China spend 50% of their income on food.

A. gradually

B. approximately

C. harmfully

D. curiously

答案：

A. gradually

(答案→)B. approximately

C. harmfully

D. curiously

解析：A. gradually逐渐地，B. approximately大约，C. harmfully有害地，D. curiously好奇地，句意：虽然中国人民的生活标准已经大大的提高了，大部分贫穷的家庭还是将50%的收入花在食物上。所以选B。