risk是可數(shù)名詞嗎

　　Any investment involves an element of risk.

　　任何投資都有一定的風險。

　　Hundreds of thousands of people are at risk.

　　有幾十萬人正處于危險中。

　　It seems only right to warn you of the risk.

　　似乎應該警告你有風險。