They felt sleepy when exposed to regular beeps.

当听到有规律的蜂鸣声时，他们会感到困倦。

youdao

They are alert at bedtime and sleepy when it is time to get up, and this may have nothing to do with how fatigued their bodies are, or how much sleep they must take to lose their fatigue.

他们在睡觉的时候很清醒，到了该起床的时候很困倦，这可能与他们的身体有多疲劳，或者需要多少睡眠才能消除疲劳无关。

youdao

When we get sleepy, we'll sleep. Now hush.

我们困了就睡。现在不要说话了。

youdao

Yes. When we get sleepy we'll sleep. Now hush."

是的，困了我们就睡，“,“不要说话了，“

耶鲁公开课 - 1945年后的美国小说课程节选

Domestic demand was sleepy when consumer credit was unknown and a combination of a weaker currency and high barriers to trade made imports too expensive.

ECONOMIST: Brazil

The sensors can detect when the driver becomes sleepy because your heart rate slows down considerably.

FORBES: Sensors To Detect Driver's Fatigue

But the next morning she said she was surprised when Millie was very sleepy and appeared to be coming down with the cold.

BBC: Millie Martin murder: Mother gives evidence