親眼所見！known 後接不同的成分，就會呈現參差不齊的意思
Known 既是 know 的過去分詞，又是常見的形容詞。當 known 作形容詞時，與 to、as 和 for 的連用常常讓人撲朔迷離，很多人甚至經常把它們互換使用，其實它們還是有很大的區別。
一、be known as
一般來說 be known as 表示某人或某物因什麼而被知道，意為“被稱為”，通常是某種具有特殊含義的身份標識，例如：
His name is Robert， but he is known as Bobby。
雖然他的名字叫羅伯特，但他被稱為鮑比。
She was known as the Iron Lady。
她被稱為鐵娘子。
Christopher is commonly known as Kit。
克里斯托弗通常被稱為基特。
This design came to be known as the Oriental style。
這種設計後來被稱為東方風格。
Internet addresses are also
known as URLs。
網址也被稱作URL。
二、be known to
1. 當 be known to 中的 to 作不定式的標識時，表示某人或某物因自己的某個動作或狀態特性而被知道，意為“眾所周知”等，例如：
This drug is known to have adverse side effects。
眾所周知，這種藥具有不良副作用。
The drug is known to cause a mild cardiac seizure。
眾所周知，這種藥會引起輕度的心臟病發作。
He was known to eat the same restaurant everyThursday。
大家都知道他每個星期四都在同一家餐館吃飯。
She was known to cancel interviews at the last minute。
大家都知道她在最後一刻取消了面試。
2. 當 be known to 中的 to 作介詞時，後面通常跟人，表示已經某事情已經被某人知道，意為“為…所知”，例如：
He wants to keep them all in his office for reasons best known to himself。
他想把他們都留在他的辦公室裡，原因只有他自己知道。
The suspect‘s violent past was known to police。
警方知道嫌疑犯的暴力行為。
Rabies has been described as one of the most terrifying diseases known to man。
狂犬病被稱為人類已知的最可怕的疾病之一。
三、be known for
Be known for 是三個中最好理解的一個，意為“因…而出名”，是一個褒義的短語，通常指某人的成就或某物的特徵使某人或某物為眾人所知，例如：
He is better known for his film and TV work。
他的影視作品更為出名。
She is best known for her work on the human brain。
她在對人腦的研究方面最為知名。
The French are known for their love of their language。
法國人熱愛自己的語言是出了名的。
This plant has long been known for its medicinal qualities。
這種植物一直以其藥性而聞名。
需要引起注意的是，並不是所有的 known for 都意為“因…而出名”，特別是 for 後面接的一個時間段，它表示的某種狀態（已知的，未知的）持續了一段時間，常用於否定句中，因此要根據具體的上下文來判斷，例如：
The answer to that question
may not be known for days。
這個問題的答案可能好幾天都沒人知道。
The true cost of these experiments to the environment will not be known for years to come。
這些實驗對環境造成的真正損失在未來幾年內還不得而知。
四、思考題
1。 He is known _____ the police because of his previous criminal record。
a。 as
b。 to
c。 for
2。 The director is known _____ his first film。
a。 as
b。 to
c。 for
關注外語行天下，後期會更精彩。
