v. （使）产生污渍,玷污,认出
His boots were spotted with mud.
他的靴子上沾有泥渍.
The scandal spotted his character.
那件丑闻玷污了他的人格.
She spotted her friend in the crowd. ------------------------------------这句就是
她在人群中认出了她的朋友.根据不同语境来替换。如果是强调突然发现——强调突然性，可以用spot但只是平常语气，用find比较好