and 和；????than 比；????or 或；????but 但是；????so 于是；????provided 如果；????unless 如果不；????if 如果；????only 可是；????otherwise 否則；????whether 是否；????because 因為；????therefore 因此；????even though 即使；????although 雖然；????however 然而；? ?untill 直到；????as long as 只要；????whenever 無論何時；????wherever??無論何地；????neither nor 既不..也不；????either ... or 非此,,,即彼；?????not only ... but also 不僅...而且；????when 在...時候；????while 在...期間；????as soon as 一...就；????nevertheless 雖然...但是；????unless 除非；????since ...以來...；????so ... that 如此...以至；????? ? ? ?