There's no way of knowing why one man makes an important discovery ________ another man, also intelligent, fails.
______by many people,the spokesman made an exciting speech.
At the same time,they are taking strong _______ to protect wildlife resources.
To enjoy the scenery,he would rather _____ long hours on the train ___ travel by air.
His suggestion ____ the meeting be delayed was turned down.
-— How far apart do they live? ---- _______ I know,they live in the same neighbourhood.