Everymeans____triedoutbutneverwithsuccess,asfarasmyknowledgegoes.
C
【句意】就我所知，每种方法都试过了，但都没有成功。
【难点】means虽以s结尾却是单数形式，因此谓语动词应选用第三人称单数。
We expect Mr. White will ____Class One when Miss Jane retires.
Is Tom at school today?No, He ’s at home ______ he has a bad cold.
I hope you will spend as much time as you can ________ your English.
That ’s ________exciting news that I’d like to tell everyone to share the joy.