The answer has been lurking around in the scientific literature since the 1970's when Michael Kaplan reported that an enriched environment enhances the number of new neurons.

其实这个答案一直潜藏在科学文献中，70年代，卡普兰就报道了丰富的环境可以提高神经元的数目。

youdao

He has little charm, and has been lurking far too long in the shadows to acquire the telegenic qualities Poles now seek in a president.

ECONOMIST: Poland

For as long as Mr Edwards has been dealing, prosecutors have been lurking.

ECONOMIST: Louisiana politics

But his recent behaviour has sharpened doubts that have long been lurking.

ECONOMIST: Bagehot