A poor diet increases the likelihood of (developing) serious health problems. [=a poor diet makes it more likely that you will develop serious health problems]不良饮食增加出现严重健康问题的概率。

There is no likelihood of that happening. [=there is no chance of that happening]不可能发生那种事。

There is every likelihood that he will be reelected. [=he will almost certainly be reelected]他极有可能再次当选。

In all likelihood it will rain tomorrow. [=it is very likely that it will rain tomorrow]明天十有八九要下雨。

There is a strong likelihood that he will be reelected.他再次当选的可能性非常大。