【单选题】

A farmer carelessly lost an expensive gold watch in the barn on the farm, where he searched for everywhere but in vain.

So he put a 21 on the gate of the farm: whoever finds the gold watch will be 22 100 dollars.
Facing the 23 of the handsome reward, people tried their best to look for everywhere. 24 ,the grain was piled like a hill along with bales of 25 , so if they wanted to find the gold watch, it would be like fishing for a needle in the 26 . When the sun set, the gold watch was not found yet,
They took pains but found 27 , so they began 28 the watch was too small, the barn was too large and the straw was too thick. It was getting 29 , that they were still unable to find it.
So they 30 the temptation of 100 dollars one by one. But only a small boy in 31 clothes was still not discouraged, but kept 32 it in the grain. He had nothing to eat throughout the day. In order to solve the family problem, he was 33 to find the gold watch and let his par-ents, brothers and sisters have a full meal.
The night was already getting late and the boy was also tired. He was 34 in the straw to have a rest 35 he heard a strange "tick-tock". He immediately held his breath and listen 36.
It was quieter in the barn while" tick-tock" 37 clearly. The boy 38 the sound, found
the gold watch buried in the depths of the grain and finally got the 100 dollars. Like the gold watch in the barn, 39 has existed around us and spread in every corner of life. Only we are calm and 40 look for it, can we find it.
21. A. notice
B. signal
C. information
D. photograph