She is certain(ly) the most beautiful one around the world.

certainly 是来修饰后面的 the most beautiful one 的.be是系动词,后面跟形容词,如果跟副词,副词是修饰后面的形容词,动词之类的.
He is really happy.really来修饰happy He is always helping others.always修饰helping了解，很感谢。很贪心地再问一个问题…一道选择题：Which is _____ to learn,swimming or fishing?A.easy B.more easily C.the easier...我觉得是选C但是同学说选B，虽然不清楚C里为什么比较级前加了the，但是我觉得不应该用副词啊。to learn是一个动词不定式吧？副词可以修饰动词不定式？并且不是有个句型是it is adj. to do sth吗。。还是关于be动词和副词的问题，呵呵。。我觉得哪个都不对， 应用 easier ，be+形容词，如果有of the two, 就用the +比较级例如：This ruler is the shorter of the two.这句话如果是 Which is the easier to learn of the two, ...? 就选C。但是这句话这么问，有点别扭。老师也是这么说的，要加of the two，但是总该不会用副词吧，哈哈！非常谢谢你哦~