risk是可数名词。
riskn.危险；风险；危险人物；会带来风险的事物；
v.使…冒风险(或面临危险)
You have no right to take risks with other people\'s lives.
你没有权利拿别人的生命去冒险。
It was a difficult decision but we decided to risk it.
这件事决心难下，但我们决定冒险一试。
There is still a risk that the whole deal will fall through.
整桩买卖化为泡影的风险仍然存在。
