People who often stay up late are to suffer from heart attacks than those who are not.A.

问题补充：

People who often stay up late are to suffer from heart attacks than those who are not.

A. six times more likely

B. as likely six times

C. six times as likely

D. more likely six times

答案：

(答案→)A. six times more likely

B. as likely six times

C. six times as likely

D. more likely six times

解析：考查倍数：倍数的表达：倍数+adj比较级+than…,先是倍数，排除BD项，因为句中有than，应该是比较级，句意：经常熬夜的人比那些不熬夜的人更容易得心脏病。选A。