You can be alert, even though the intensity of the stimulus is quite low.

即使刺激的强度很低，你也要保持警惕。

youdao

We must be alert to the possibility of danger.

我们必须认识到危险的可能性。

《牛津词典》

It's a very intense job, and they have to be alert every moment.

这是高度集中的工作，他们需要时刻保持警惕。

youdao

The U.S.State Department has issued a fresh travel alert for India, saying the U.S.government continues to receive information that terrorist groups may be planning attacks here.

VOA: standard.2009.10.30

Because it's a very intense job they have to be alert every moment.

因为是高度集中的工作,他们需要时刻保持警惕。

普林斯顿公开课 - 国际座谈会课程节选

"With that,I expect the security agencies to be 24-hours alert.

VOA: standard.2009.07.30

Policy makers must also be alert to several other necessary components of health-care sustainability.

WSJ: How Asia Can Get Health Care Right

"It was on my radar to be alert" to that scenario, the CEO adds.

WSJ: What to Do When Your Company Hires a New CEO

Be alert enough to avoid stepping in them, and they will generally disappear on their own.

FORBES: Big Ego, Big Business: 6 Famous Failures, and 4 Key Ideas For Keeping Your Ego in Check