to build or create again something that has been damaged or destroyed

The post-war government had the enormous task of reconstructing the city. 战后的政府担负着重建该城市的艰巨任务。

to change a system or organization completely, so that it works more effectively

They were given the task of reconstructing the city's public transport system. 重建该市公交系统的任务交给了他们。

If you reconstruct something that has happened in the past, you combine a lot of information in order to get a complete description of what happened.

The police tried to reconstruct the crime using the statements of witnesses. 警方设法利用目击证人的陈述来重现犯罪过程。