as
prep.（介詞）
(表示時間)當(dāng)還是…的時候
As a schoolboy,he showed every sign of genius.
當(dāng)他還是個小學(xué)生的時候,就顯示出了天資聰慧.
(表示方式)以…的身份,以…資格,作為; 以…形式,以作為; 以…角色,扮演…角色; 如同,像
(表示結(jié)果)成為,看作,看成
We had better treat it as a joke.
我們最好把它當(dāng)作玩笑.
(表示目的)為了,以…為目的
The dykes were built as a protection against the sea.
建筑堤壩是為了防止海水泛濫.
(表示舉例)例如,諸如…之類的
We talked about such subjects as the weather.
我們談?wù)摿酥T如天氣之類的話題.
conj.（連詞）
在…期間,當(dāng)…時候
I was coming in as he was going out.
我進(jìn)來的時候,他正出去.
盡管,即使,雖然
Intelligent as you are,I suspect you will fail.
盡管你聰明,我猜想你會失敗.
像…一樣
由于,因為
As you weren't there I left a message.
因為你不在那里,我留了個信兒.