Have a few parts left over at the end 的英文到底是甚麼意思?

請看看以下的英文笑話。

5 surgeons are taking a coffee break:

1st surgeon says, "Accountants are the best to operate on because when you open them up, everything inside is numbered."

2nd surgeon says, "Nah, librarians are the best. Everything inside them is in alphabetical order."

3rd surgeon says, "Try electricians, man! Everything inside them is color coded."

4th surgeon says, "I prefer lawyers. They're heartless, spineless, gutless, and their heads and butts are interchangeable."

5th surgeon says, "I like engineers.. they always understand when you have a few parts left over at the end."

前四個外科醫生說的話很容易理解，但第五個外科醫生說的話就沒那麼容易理解了，到底 have a few parts left over at the end 的英文是甚麼意思?

意思就是當工程師建造或修復了一個機器後常常會忘了把某些小螺絲或小零件放回機器裡面正確的地方，到最後才發現這些零件還在外面，但反正這些零件不會造成機器無法運作，工程師索性就不把這些零件歸位了。

所以這個外科醫生的意思是 "我喜歡工程師，因為當我不小心忘記把工程師病人體內的某個小器官放回身體裡面就完成手術，工程師是會理解的，因為工程師也會發生類似的錯誤。也就是說，當我在對工程師動手術時，我不用太細心。"

問題是雖然機器裡面有些小螺絲或零件是可以缺少的，但人體的器官應該是甚麼都不能缺少吧?

The 5th surgeon likes the fact that he does not have to be careful if he forgets to put something back. The surgeon likes that he does not need to worry about missing a little piece or thing here and there when operating on engineers because engineers will understand.

"I have a few parts left over" 的意思就是 "I have a few parts that I should have used, but I did not use them."

以下是用 left over 的例句:

When working on a machine I always have left over screws and other little parts. Trying to figure out where they belong in the machine in the very end is a pain. However, engineers do not worry about it because the machine will work even without every little screw.

這個笑話是不是很好笑? 真是笑死我了~