He is no fool at all; ，he is the smartest boy I have ever seen.
A. in addition
B. in fact
C. in particular
D. in short
网友回答
A. in addition
(答案→)B. in fact
C. in particular
D. in short
解析：考查与in有关的短语。in addition 的主要意思为“除此之外；in fact 事实上in particular 尤其是
in short简而言之。句意：他不是个傻子，事实上，他是我见过的最聪明的男孩。故选B