制导方法 视频:谁能帮我翻译个句子？把下面的句子译成英文（不要机器和网上翻译的）

He obtained his Doctor Degree in his 20s, and has been working hard all his life.
I am sure that he should be very satisfactory when recollecting his past.

博士一词应是译 Doctor ，PhD 只是博士中的较低而不分科一种，因中文没有注明其种别和职业，译 Doctor 为佳。其他较高级的如 LLD 法学博士，MD 医学博士，D Litt 文学博士，D.Sc , ScD 理学博士， D Music 音乐博士也可考虑。

He obtained his Doctor's Degree in his 20s, and has been working hard all his life.
I believe that he should be very satisfactory when recollecting his past.

He got the Ph.D at his twenties, and was working hard all his life time.So I thought that he would be very much satisfactory every time he recalled his past.

He got his Ph.D in his 20s, and has worked hard all his life. Therefore I think he would be very satisfied when he looked back.

He got Doctor's Degree in his 20s, and has been working hard all his life.
I think he should be very satisfactory when he recollects his past.