作为翻译词组题型来讲，善于……必须是“be good at”吗？ 翻译为do well in有错吗？

作为翻译词组题型来讲，善于……最好译成be good at，请仔细分辨下列例句：
good at:  善于(擅长)

例句与用法:
1. She is no less good at swimming than Mary.  
她和玛丽一样擅长游泳。

2. The soldier was good at playing fife.  
这名士兵善于吹笛子。

3. The writer is not very good at writing dialogues.  
这个作家不太擅长写对白。

4. If I have get the picture, then English people is nit good at learning language.  
要是我明白了这意思，那就是说英国人不善于学习语言。

5. She is good at needlework.  
她擅长刺绣。

6. I'm good at it.  
我做这个很在行。

7. She is good at crochet.  
她擅长钩针编织。

8. He is good at his job but he seems to lack confidence.  
他工作不错，但似乎缺乏信心。

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do well in:  在...方面干得好

例句与用法:
1. You have to be highly competitive to do well in sport nowadays.  
如今必须有高度的竞争意识才能在体育运动中取胜.

2. What a child should do, above all, is to do well in his studies.  
小孩子该做的最重要的事是学好功课。

3. I see Britain did well in the discus.  
我看英国队在铁饼项目中表现不错.

4. Of the 40 students, some do well in study, and the others are playing around.  
四十个学生中，有一些功课很好，其余的都很混。

5. He would probably do well in the examination only he gets very nervous.  
他要不是考试很紧张, 成绩可能不错.

不错，是有一定区别，

不错，是有一定区别，

谢谢daoyou1 的精彩解答！

谢谢各位

be good at 和 do well in区别
be good at v.擅长
do well in在……成绩好,在...做得好，在……表现好
现以例子来说明它们意思的区别：
You are good at English你英语好，你擅长英语。
You do well in English你英语成绩好（英语成绩好，并不表示你的英语就很好了，比如你在学小学一年级的英语时很刻苦，成绩好，但尽管你的成绩很好，但你不能说你英语就很好了，你不能说你你擅长英语，毕竟你学的只是小学一年级的英语，另外，说不定会半途而废呢，说不定你小学二年级英语成绩很差呢。）
请再多看些例子来体会他们意思上的区别
Peanuts do well in this area.
这一带花生长得很好。
She was resolved to do well in the factory.
她决心在厂里好好干。
The scheme will do well enough in good hands.
在能人手里，这计划实施起来一定很不错。
Well, steven is not doing well in his second vault.
唉，斯芬在第二次（撑竿）试跳时没有跳好。

Be you any good at business?
你做生意行吗？
a good executive must be good at decision making.
优秀的领导者必须善于决策。
Such good chance shouldn't be sniffed at.
这样好的机会你决不可小看。
The boy used to be no good at arithmetic.
过去那男孩算术总是不行。
The important thing is to be good at learning.
重要的是善于学习。
We should be good at learning from each other.
我们应该善于互相学习。
We should be good at separating friends and foes.
我们要善于区分敌友。