Language Points:

Language Point 1 
Dickens might have created Charlie Chaplin's childhood. (Para. 1)
Meaning: When he was a child, Charlie Chaplin lived in great poverty, which was like the misery described in Dickens' novels.

might have + V-ed: used to say that something was possible in the past, but it did not in fact happen
The plan might easily have gone wrong, but in fact it was a great success.
这个计划可能很容易失败，可事实上却非常成功。
They might have chosen anyone for the job, but they picked me.
他们也许可以选择其他任何人做这工作，可是他们选择了我。
Language Point 2 
... have provided more applause (and profit) where Chaplin is concerned than the land of his birth. (Para. 2)
Meaning: ... Chaplin was more successful in other countries than in his motherland.
to provide applause and profit where sb. is concerned
给予某人掌声和收益
Our society should provide more applause and reward where the upholders of justice are concerned.
我们的社会应给予伸张正义者更多的掌声和奖励。
where …is concerned: as far as … is concerned 就…而言，涉及到，
Where money is concerned, I always try to be very careful.
Language Point 3 
Certainly middle-class audiences did; the working-class audiences were more likely to clap for a character who revolted against authority, using his wicked little cane to trip it up, or aiming the heel of his boot for a well-placed kick at its broad rear. (Para. 3)
Meaning: There is no doubt that middle-class audiences thought so (Chaplin's Tramp was a bit crude); this character was more popular among working-class audiences because he showed his discontent with authority by using his little cane to make them fall or by kicking them in the rear.
Please compare "certainly" with "surely".
certainly  ad.  more often expressing the idea of "definitely" and "really"
surely  ad.  more often expressing surprise, doubt or relief (esp. in British English)  
I am certainly not inviting her to my party. I've never liked her.   我肯定不会邀请她来参加聚会，我从来不喜欢她。
He certainly impressed me. I thought he was very bright and talented.   他给我印象很深，是个聪明能干的人。
Surely, you aren't going out like this, are you?   你不会就这样就走出去吧？
Surely, you want that too, if you were fond of her.   如果你喜欢她，你也会要那个（东西）。 
aim at :
1) point or direct (a gun, etc.) towards (sb. or sth.)    瞄准
She aimed a kick at the cat when no one was looking.   
没人看见时，她对准那只猫踢了一脚。
I didn't mean to hit the dog. I was aiming at the tree.  
我不是故意要射那条狗，我的目标是那棵树。
You will have to aim your gun more carefully at the chosen object.   
你得把枪更仔细地瞄准选择好的物体。
2) make an effort towards (sth. or doing sth.); try to achieve (sth.) 努力
The factory must aim at increasing production this year.
这家工厂今年必须力求增加生产。
You should always aim at doing your job well. 你应该永远力求把你的工作做好。
Language Point 4 
... Chaplin's comic beggar didn't seem all that English or even working-class. (Para. 3)
Meaning: ... Chaplin's amusing character, the beggar, wasn't like an Englishman very much, neither was he like a working-class person.

(not) all that —  (not) very, (not) particularly; usu. used in statements with negative meaning when you want to weaken the force of what you are saying     并不…
Things aren't all that good.  事情并不那么顺利。
He wasn't all that older than we were.  他并不比我们老多少。
He said it would not be all that difficult to reach a peaceful conclusion to the conflict.  
他说就此冲突达成和平协议并没有那么困难。
Language Point 5
English tramps didn't sport tiny moustaches, huge pants or tail coats: European leaders and Italian waiters wore things like that. (Para. 3)
Meaning: English tramps didn't wear tiny moustaches (hair which a man grows on his upper lip), very big pants or tail coats: these were something European leaders and Italian waiters wore; therefore, Chaplin's beggar didn't look like an English tramp.
Please note that "pants" is American English and always in the plural form whereas British English-speaking people prefer to say "trousers". “Pants” in British English refer to underwear worn under one’s trousers.
sport  v. wear something often in a way to have people notice it  
The front of the car sported a Japanese flag.  这辆车前面插着日本国国旗。
He wore rimless glasses and sported a neat grey moustache, which looked very impressive.  
他戴着无边眼镜，留着整齐的灰色胡子，非常引人注目。

Language Point 6 
... the Tramp's quick eye for a pretty girl had a coarse way about it that was considered, well, not quite nice by English audiences—that's how foreigners behaved, wasn't it? (Para. 3)
Meaning: ... In the eyes of English audiences, only foreign people looked at pretty girls in such a crude way as the Tramp did.
one’s quick eye for sb./sth：瞟某人/某物的眼神
The little boy’s fixed eye for the food on the table revealed how hungry he was at the time. 
小男孩一动不动盯着餐桌上食物的眼神说明他当时有多么饥饿。
Language Point 7 
But for over half of his screen career, Chaplin had no screen voice to confirm his British nationality. (Para. 3)
Meaning: Since more than half of the roles Chaplin played were in silent films, therefore there was no way to confirm that he was British.
Language Point 8
He was an immensely talented man, determined to a degree unusual even in the ranks of Hollywood stars. (Para.5)
Meaning: He was a man of great talent, whose determination seemed unusual even among the Hollywood stars.
ranks  (pl.) the members of a particular group or organization 
成员, 行列，阶层
We have a number of international players in our ranks.
我们的成员里有很多国际选手。
At 50, he was forced to join the ranks of the unemployed. 
50岁时他被迫加入了失业者的行列。
There were serious divisions within the party's own ranks. 
在这个党的成员内部存在严重的分歧。
There is great concern about safety among the ranks of racing drivers.
赛车手对安全很担心。
to a / some degree — partly    有些，稍微
I agree with you to some degree. 我有些同意你的看法。
Most pop music is influenced, to a greater or lesser degree, by the blues.  
大多数流行音乐都多少受到布鲁斯（蓝调）的影响。
Language Point 9 
He already had the urge to explore and extend a talent he discovered in himself as he went along. (Para. 5)
Meaning: He then had a strong desire to further discover and develop his talent as he progressed in his career.

have the / an urge to do sth. — have a strong desire to do sth.   极想…
He had a powerful urge to compete and succeed.
他有强烈的竞争并获得成功的欲望。
He has an urge to become a movie star. 他有成为电影明星的欲望 / 他十分想成为电影明星。
extend  v. 
1) make sth. longer or larger, or last longer   扩大, 延长
There are plans to extend the no-smoking area.   有计划要扩大禁烟区域。
The show has been extended for another six weeks.  这个演出又延长了六周。
Careful maintenance can extend the life of your car by several years. 
细心保养可使车的使用寿命延长好几年。
2) stretch part of your body, esp. an arm or a leg, away from yourself  伸出
He extended his hand to the new employee. 他向新来的雇员伸出手去。
He extended his arms in front of him as if he were praying to God.
他向前伸出双臂, 好像在向上帝祷告求助。
3) make sb. / sth. use all their effort, abilities, supplies, etc.  尽全力
Jim didn't really have to extend himself in the exam.
对于那次考试吉姆真的不必尽全力。
Hospitals were already fully extended because of the epidemic.
由于疾病流行，医院已尽了全力。
Language Point 10
"It can't be me. Is that possible? How extraordinary," is how he greeted the first sight of himself as the Tramp on the screen. (Para.5)
Meaning: When Charlie first saw himself acting the role of the Tramp on the screen, he was surprised and couldn't believe it was him.
greet  v.  1) (with) react to sb. or sth. in a particular way   反应
The changes were greeted with suspicion.  人们对此变化持怀疑态度。
They greeted the joke with laughter. 他们对这个笑话报以笑声。
2) say hello to sb. or to welcome them    问候, 致敬
He greeted all the guests warmly as they arrived.
客人到达时他热情地向所有人问好。
The winning team was greeted by cheering crowds. 人们欢呼着欢迎获胜的队伍。
Language Point 11 
Lifeless objects especially helped Chaplin make "contact" with himself as an artist. (Para. 6)
Meaning: For Chaplin, everyday things were especially useful in his creations.
Language Point 12 
The two were hard to combine and sometimes—as in his early marriages—the collision between them resulted in disaster. (Para. 7)
Meaning: It's difficult to deal with the conflict between the desire for love and the fear of betrayal and sometimes, as in his early marriages, it led to personal misfortune.
Language Point 13
Yet even this painfully-bought self-knowledge found its way into his comic creations. (Para.7)
Meaning: Even the misfortune in his personal life was used by him in creating his comic movies.
find one's way into — arrive or get somewhere after some time  来到（某处），进入
Rivers find their way into the sea.   条条江河通大海。
Computers have found their way into most ordinary families. 
计算机已经进入大部分普通家庭。
He eventually found his way into acting. 他终于进入了演艺界。
Language Point 14
The Tramp never loses his faith in the flower girl who'll be waiting to walk into the sunset with him…(Para. 7)
Meaning: The Tramp always believes that the flower girl will be waiting to join him to enjoy their life together…
Here the author implies that like the Tramp, Chaplin never lost his faith in life and love and was sure to find someone to share the rest of his life with. When we say "people walk (off) into the sunset (together)", we mean their relationship will last and they will live happily.
to walk into the sunset with sb: 与某人共同走进夕阳之中/与某人白头偕老
Those bathed in love wish to walk off into the sunset with each other. But there are always some who change their minds after marriage. 
沉浸在热恋中的人都希望与对方白头偕老，但是结婚后总有一些人会改变主意。

lose (one's) faith in —  lose one's trust or confidence in sb. or sth.  失去信任
After the trial, his family said they had lost all faith in the judicial system. 
审判之后，他家人说他们对司法系统失去了信心。
We've lost faith in him.  我们再也不相信他了。
People have lost faith in the British Parliament. 人们对英国议会已失去了信任。
Language Point 15
It's a relief to know that life eventually gave Charlie Chaplin the stability and happiness it had earlier denied him. (Para. 8)
Meaning: We are happy to learn that in spite of his early misfortunes he finally found the woman who brought him the stability and happiness in his later life.
Language Point 16 
In Oona O'Neill Chaplin, he found a partner whose stability and affection spanned the 37 years age difference between them... (Para. 8)
Meaning: When Chaplin chose Oona O'Neill as his wife, he found loyalty and love, despite a 37-year age difference between them...
find … in sb. — discover that sb. has certain qualities   发现某人有（特质）
We have found in him a man of trained hand, eye, and brain; disciplined and good mannered.  
我们发现他是一个训练有素的人，有手艺、有眼光、有头脑，同时也具有良好的修养，彬彬有礼。
We have found in her a woman of wit and intelligence, with a master's degree in business administration.  我们发现她是一位风趣而智慧的女士，有商务管理硕士的学位。
Language Point 17
As Oona herself was the child of a large family with its own problems, she was well-prepared for the battle that Chaplin's life became as many unfounded rumors surrounded them both — and, later on, she was the center of calm in the quarrels that Chaplin sometimes sparked in their own large family of talented children. (Para.8)
Meaning: Oona herself had experienced many problems in her own family before marrying Chaplin. So she was able to deal with the problems in Chaplin's life. For example, at that time they were both faced with many groundless rumors. And when Chaplin sometimes caused quarrels with his many talented children, it was Oona who  brought peace back to the family.
unfounded  a. not based on fact   无事实根据的, 毫无理由的
I'm pleased to see that our fears about the weather proved unfounded.   
我很高兴地发现我们对天气的担心是毫无理由的。
The rumors were totally unfounded that he is going to resign.
他打算辞职的谣传是毫无事实根据的。 
Language Point 18 
The police recovered it with more efficiency than Mack Sennett's clumsy Keystone Cops would have done... (Para. 9)
Meaning: The police found Chaplin's body much more quickly than the silly policemen in Mack Sennett's comedies would have...

"Keystone Cops" refer to a group of police officers who appeared in Mack Sennett's films from 1914 to the early 1920s. They made a lot of mistakes and did stupid but funny things.