His smile faded as he explained, and a hard edge crept into his voice.

他解释着，嘴角的笑意有些黯淡，某种生硬的味道在他的语气中蔓延开来。

youdao

I tried to concentrate as he explained the lab we would be doing today.

我努力把注意力集中在他对我们今天要做的实验的讲解上。

youdao

I tried to concentrate as he explained the lab we would be doing today.

我努力把注意力集中在他对我们今天要做的实验的讲解上。

youdao