Unless in uniform, he doesn't look like a policeman.
除非穿上制服,要不他看起来不像警察。
You're likely to see a cheerful message or two hanging on the wall.
很有可能会看到一两条挂在墙上的格言。
Shortly after this the famous H. M. S. Challenger expedition established the study of the sea-floor as a subject worthy of the most qualified physicists and geologists.