Joe was an old man．The 75﹣year﹣old lived very happily in a village and had a beautiful family．Joe had four grandchildren，and they visited him during their holidays．

During one vacation，Joe was preparing his home for the kids：cleaning and buying their favorite foods．After he finished working，he realized he lost his favorite watch．The watch was a gift from his wife when their first child was born．Joe loved the watch very much，especially after his wife's death．He was very upset about losing it．

Once his grandchildren came，they promised him they would find the watch．

One granddaughter asked："Grandpa，do you remember when you saw the watch last before it went missing？"

"I guess when I was cleaning the barn（谷仓）！"Joe replied．

The children looked for more than two hours with Joe，but they could not find it．The kids were now also sad，but they tried to comfort（安慰） their grandfather．

One grandson went back to the barn to search again．Joe asked why he was going there a second time．But the little boy just asked the others not to follow him and to remain silent．

He was there for about fifteen minutes and then rushed to his grandfather．He found the watch and happily gave it to Joe．

Joe was surprised and asked how he was able to find it．The little boy replied："I sat there without making a noise，and the barn was so silent．After a few minutes，I heard the‘tick，tick' sound and found the watch．"

Joe hugged and thanked the little boy．

49．From Paragraph 2，we learn that Joe　　．

A．knew his grandchildren very well

B．liked doing housework very much

C．got tired of his grandchildren's visits

D．looked forward to his grandchildren's visits

50．Why did Joe feel upset when he found the watch was lost？　　

A．Because it was very expensive．

B．Because it was full of memories with his wife．

C．Because it was a gift from his first child．

D．Because it had been with him since he was born．

51．How did one of the grandchildren find the watch？　　

A．He cleaned the barn carefully again．

B．He searched the barn carefully for two hours．

C．He made no noise and followed the ticking sound．

D．He asked other children for help．

52．What does the story mainly tell us？　　

A．Helping those in need can make you feel good．

B．We must learn to be silent and wait in order to help others．

C．Believe in yourself and you can surely succeed in the end．

D．Silence sometimes is more powerful than using your voice．