问题补充：
He went back to the hall to try hisat finding his lost gold watch，but never found it.
A. best
B. success
C. result
D. luck
答案：
A. best
B. success
C. result
(答案→)D. luck
解析：短语try one’s best(努力,尽力)后常接to do sth.;try one’s luck at doing sth.意为 “碰碰运气做某事” 。B 、C两项不符合题意。
