The meaning of a word can be guessed according to the context, so you will not ______ refer to a

dictionary the next time _______ you come across a new word. [ ]

A. really, when

B. exactly, that

C. likely, which

D. necessarily, /

乙型肝炎疫苗可以预防乙型肝炎，也可以预防丁型肝炎。