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

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：考查sb. be likely to do sth.某人很可能会做某事。Possible和probable不能用人作主语，be sure to do.肯定会，一定会，sure无比较级变化，所以不能和more连用。选A。