Back then I was reading a popular set of basic science books called a Hundred Thousand Whys.

那时，我正在读一套流行科学读物：《十万个为什么》。

youdao

Back then I was reading a popular set of basic science books called a Hundred Thousand Whys.

那时，我正在读一套流行科学读物：《十万个为什么》。

youdao