the traditional goal of science is to discover how things are ,not how they ought __
问题描述：
the traditional goal of science is to discover how things are ,not how they ought __
a to b tobe c not touch d not do
ought to 是助动词 不能做谓语是吗
答
选b ought to是情态动词哦 是情态动词不能做谓语是吗情态动词是不能单独做谓语的，需要和后面的动词构成合成谓语