Of one thing I am certain hard work contributes to good results.
A. as
B. what
C. which
D. that
网友回答
A. as
B. what
C. which
(答案→)D. that
解析：主要测试同位语从句。此题属于结构的不正常化，正常应该是I am certain of one thing hard work contributes to good results。译文如下：我确信努力工作会带来好的结果。结合译文可知one thing 的具体内容既是后面句子的内容，属于所学的同位语从句。