The levers and light were set up in exactly the same way except that this time it was only Doris who could see the light indicating which lever to press first.

杠杆和光的设置完全一样，只不过这次只有多莉丝能看到先按哪个杠杆的灯的指示。

youdao

If the light flashed on and off several times, the dolphins were supposed to press the left-hand lever followed by the right-hand one.

如果灯亮了又灭了好几次，海豚就应该先按左手的杠杆，再按右手的杠杆。

youdao

A light lit above the lever indicating drugs were available to be administered.

在操作杆上面亮着一盏灯，指示药物能够被取用。

youdao

But when Dr Ciccocioppo took half the rats back to their drug den, and then flashed the light and sounded the beep, the animals immediately set about pressing the lever that they thought would deliver cocaine.

ECONOMIST: Addiction