Police have asked residents to keep aneyeoutfor anything suspicious.
警方要求居民密切注意一切可疑的情况。
《牛津词典》
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If neighbors are strangers to one another, they are less likely to sweep the sidewalk of an elderly couple living next door or keep aneyeoutfor young trouble makers.
If you've explored the area before, keep aneyeoutfor familiar sights—you may be surprised how quickly identifying a distinctive rock or tree can restore your bearings.