问题补充：
Jack took part in the speech contest and, is more surprising, won the first place.
A. that
B. what
C. which
D. it
答案：
A. that
B. what
(答案→)C. which
D. it
解析：这题考查非限制性定语从句，非限制性定语从句也是插入语，去掉后这句话是：Jack took part in the speech contest and won the first place.是个完整的句子，which指代的是won the first place.选C。
