重点讲解：
1. hesitate to do sth. （因有顾虑而）不愿意（做某事）；
Don't hesitate to make comments or suggestions if you have any.
有意见尽管提好了。
2. ought to do sth. 应当，应该；
We ought to follow her good example.
她是个好榜样，我们应当仿效她。
3. go through 经历，经受（尤指苦难或艰难时期）；
I went through my midlife crisis about four or five years ago, when I was forty.
四五年前，在我40岁的时候，我经历了中年危机。
4. be exposed to 使暴露于（险境）；使遭受（危险或不快）；
The research councils are still considering the possibility of being exposed to some sort of reputational risk.
研究委员会仍然在考虑一些可能产生的信誉风险。