The young man always talks a lot he knew everything, which, of course, makes others unhappy.
A. once
B. even though
C. though
D. as though
网友回答
A. once
B. even though
C. though
(答案→)D. as though
解析：
试题分析:考查连词辨析。A曾经，一次；B即使；C虽然；D仿佛。根据前句的一般现在时和后面一般过去时可以判断此处是虚拟语气，所以答案选D。句意：这个年轻人总是夸夸其谈，仿佛无所不知，当然了，这让其他人很不高兴。