單項選擇題

（）, remedies must be taken to stop it as early as possible.

A.Any surge occurs
B.Any surge occurred
C.Should any surge occur
D.Should any surge occurring

你可能感興趣的試題

（）, the motion would continue indefinitely once it had started.

A.Were there loss of energy by friction
B.Since there be loss of energy by friction
C.Were there no loss of energy by friction
D.Should be no loss of energy by friction

單項選擇題

（） the bodies are, （） the friction will be.

A.The smoother；the greater
B.Smoother；less
C.The rougher；the greater
D.rougher；greater