大全637我这样的理解对吗？请教！

saharaa

637.Several studies have found that the coronary patients who exercise most actively have half or less than half the chance of dying of a heart attack as those who are sedentary.
(A) have half or less than half the chance of dying of a heart attack as those who are sedentary
(B) have half the chance, or less, of dying of a heart attack than those who are sedentary do
(C) have half the chance that they will die of a heart attack, or less, than those who are sedentary do
(D) are at least fifty percent less likely to die of a heart attack as those who are sedentary
(E) are at least fifty percent less likely than those who are sedentary to die of a heart attack

这题答案是E 而E得比较是主谓结构的比较，即谁比谁更有可能得病。但一般主谓结构的比较than后都必须补出助动词。而这里没有补出？！
我的理解是：因为这里是个主系表结构，即没有宾语，所以不会造成than 的代词指代歧义，所以不用补出助动词。
请教大牛，我这样的理解是正确的吗？

saharaa

此are非彼are ，我觉得，句子结构应该是：
patients （who exercise most actively） are at least fiftypercent less likely than those （who are sedentary） to die of a heart attack

所以我认为两者没有必然联系

sumerlaws

没看明白楼主怎么分析的，
自己做了一下。首先，后面那个who are sedentary，证明这里必须用are。选D 或E
接着就是less likely to 还是less likely than，显然是必须有than。因此我选E