《新概念》这个句子，确实和咱们学的语法规则不一样。夸克上面都没有开绿灯。

然而，had not the entrance been spotted这样的结构，还真是存在，可以说是一个古董级的存在。下面例子供参考：

Francisco de Vargas y Mexia - Wikipedia

https://en.wikipedia.org/wiki/Francisco_de_Vargas_y_Mexia

 ... where there is such panic that the population would have run away had not the gates been closed. The Pope has fallen ill with rage, and was struggling with a ...

Parliamentary Debates

 - 第 269 卷 - 第 202 页 - Google 图书结果

https://books.google.co.uk/books?id=7dkLAQAAIAAJ

 New Zealand. Parliament - 1946 - ‎New Zealand

... party 2 Had not it been that Mr. Walsh feared exposure of the other land transaction, he would probably not have divested himself of the property in question.

Verse (42:21) - The Quranic Arabic Corpus - Translation

corpus.quran.com/translation.jsp?chapter=42&verse=21

Had not it been for your Lord's giving them respite for an appointed time, He would certainly have settled their differences once and for all. The unjust will ...

Jane Austen: Pride and Prejudice, Chapter II of Volume II (Chap. 25)

https://pemberley.com/janeinfo/ppv2n25.html

Oh, sister! it is very hard to think that she might have been Mr. Collins's wife by this time, had not it been for her own perverseness. He made her an offer in this ...