You use hence to indicate that the statement you are about to make is a consequence of what you have just said.
The trade imbalance is likely to rise again in 2007. Hence a new set of policy actions will be required soon.
贸易不平衡在2007年可能会再度上扬。因此需要很快采取一系列新的政策行动。
European music happens to use a scale of eight notes, hence the use of the term octave.
欧洲音乐碰巧使用八音符节律,由此人们开始使用“八度”这一名称。
You use hence in expressions such as 'several years hence' or 'six months hence' to refer to a time in the future, especially a long time in the future.
The gases that may be warming the planet will have their main effect many years hence.
这些可能正在使地球变暖的气体,其重要影响将在许多年之后显现。