大学英语：We are on guard when they visit our homes

　2.We are on guard when they visit our homes.

　　guard 这个词既可做名词用，也可做动词用。做名词用时，意思是“看守;守卫;警惕;”做动词用时，意思是“保卫，保护;看守。”

　　1)He works as a door guard for that company. (他在那家公司做门警。)

　　2)They will give him an armed guard. (他们会给他配备一队武装卫兵。)

　　3)I was immediately on guard when father mentioned that incident. (父亲提起那件事，我就立刻提防起来。)

　　4)Police were sent to guard his house. (警察被派去守卫他的房子。)

　　5)She had been locked in her room and guarded day and night. (她被锁在房间里日夜看守着。)

　　6)The old man told his son to guard against conceit. (那位老人嘱咐他的儿子谨防骄傲。)