By the way, the "green world" long tone.

顺便把“青青世界”拖长音。

youdao

They cued their mice with a minute-long tone that was followed two seconds later by a quick, mild electrical shock.

他们让老鼠听一分钟的长音，两秒后是快速温和的点击。

youdao

When it is struck, a tuning fork produces an almost pure tone, retaining its pitch over a long period of time.

音叉被敲击时，产生几乎纯质的音调，其音量经久不衰。

youdao

" It is a long tone poem for orchestra.

VOA: special.2009.02.15

You phone a friend to let off steam, to hear 'Jemima and Jake are unavailable at the moment - please leave your name and number after the long tone'.

BBC: THE UNANSWERED CALL

The old rules no longer apply, and how Britain's "old media" deal with this challenge may set the tone for a long time to come.

CNN: Naked Harry scandal a watershed moment for UK press

But the rock star may have been growing tone-deaf long before his embarrassing revelation, says Mr Page, who has followed Mr Jackson's political career for 30 years.

ECONOMIST: Jesse Jackson