After two years’ research we now have a better understanding of the disease.A. veryB. far

问题补充：

After two years’ research, we now have a better understanding of the disease.

A. very

B. far

C. fairly

D. quite

答案：

A. very

(答案→)B. far

C. fairly

D. quite

解析：修饰比较级的只有far 和rather两个词。