单词keep-a-sharp-lookout
na.: 严密监视网络: 戒备；严加注视
Due to dense fog . Keep a sharp lookout . Navigate with caution.
由于浓雾，请仔细了望，认真驾驶。
C. to run to the bridge and keep a sharp lookout
跑到驾驶台并保持认真了望