We're singing below middle C and the ladies are singing up an octave but that's still monophonic texture-- those notes have the same names.

我们唱得比中央c低,而女士们高了一个八度,但这还是单音织体,这些音的音名是一样的

youdao

Now try middle C with your thumb.

“现在用你的拇指试中央的C”。

youdao

Now try middle C with your thumb.

“现在用你的拇指试中央的C”。

youdao