Tom is lazy and he doesn't work hard. ________,he won't pass the exam.
A.However B.Because
C.As a result D.So that
C
【解析】句意:汤姆懒惰,不努力工作。结果,他考试不及格。考查介词短语辨析题。A. However然而,表转折,可用在句子开头;B. Because因为,表原因,后接从句;C. As a result结果/因此,表结果,可用在句子开头;D. So that以便,表目的,后接从句。本句和前一句是因果关系,根据句意结构和语境,可知选C。