連詞有：as, as if/ as though

　　(1) as引導(dǎo)的方式狀語從句, 意為"以……方式;如同……那樣"，從句有時是省略句。如：

　　Do as I say. 要照我說的做。

　　I did just as you told me. 我正是照你說的辦的。

　　Air is to man as water is to fish. 空氣之于人猶如水之于魚。

　　(2) as if/as though引導(dǎo)的方式狀語從句

　　as if和as though的用法相同，都作"好像，仿佛"解。如：

　　二者引導(dǎo)的狀語從句往往用虛擬語氣，表示與事實相反。as if比as though更為常用。但也可用陳述語氣，表示所說的情況是事實或?qū)崿F(xiàn)的可能性較大。如：

　　They looked at me as if , as though I were mad.

　　他們瞧著我好像我發(fā)瘋了似的。

　　They look as if/as though they know each other.

　　他們看來好像互相認識。