I've been skating since nine o 'clock.

自9点钟以来，我一直都在滑冰。

youdao

I have been skating since eight o 'clock.

自从八点开始，我就已经滑冰了。

youdao

I have been skating since nine o 'clock.

我从九点起一直在滑。

youdao

I have been skating since nine o 'clock.

我从九点起一直在滑。

youdao