Studies show that people are more to suffer from back problems if they always sit before

问题补充：

Studies show that people are more to suffer from back problems if they always sit before computer screens for long hours.

A. likely

B. possible

C. probable

D. sure

答案：

(答案→)A. likely

B. possible

C. probable

D. sure

解析： 动词辨析，主语是people，不能和possible，probable连用，排除B,C；be sure to do,表示一定要，务必，不符合句意。所以选A。be likely to do sth.,很可能会怎样。