閱讀材料中共包含10個未完成的句子，針對每個句子中空缺部分有4個選項，請從A、B、C、D四個選項中，選出可以填入空白處的最佳選項。
One thorn（刺）of experience is worth many times of warning.
Ralph Wick was seven years old.In most things he was a fine boy，but he would cry fromtime to time.When he could not have what he wanted，he would C-31 for it.If hewas told that it would hurt him，and he could not C-32 it，he would also cry.
One day，he went with his mother into the C-33.The sun shone.The grass wascut.The flowers were starting to come out.
Ralph thought he was，for once，a good boy.A C-34 was on his face.He wished todo as he was told.Ralph helped his mother with the farm work and he was very happy.
"Now you must be tired and C-35 said his mother."Have a good rest hereand eat some cookies.I wil get a beautiful red rose for you."So his mother brought the redflower to him.When he saw his mother stil had a white rose in her hand，Ralph C-36 it.
"No，my dear，"said his mother."See how many thorns it has.You must not touch it，or you would be sure to hurt your C-37." When Ralph found that he could not havethe white rose，he began to cry，and
C-38 took it away.But he was soon very sorry.The thorns hurt his hand.It was so C-39 that he could not use it for some time.
Ralph would never C-40 this.From then on，when he wanted what he shouldnot have，his mother would point to his hand which had been hurt before.He at last learnedto do as he was told.

A.run
B.cry
C.plan
D.call