has led to是什么时态

　　The lowering of trade barriers has led to a free-for-all among exporters.

　　降低贸易壁垒导致出口商各自为政。

　　Overproduction, coupled with falling sales, has led to huge losses for the company.

　　生产过剩加上销售下降使这家公司遭受巨大损失。

　　This difference in approach has led to several political skirmishes.

　　这种方式上的差异已经导致了几场政治冲突。

　　This policy has led to a dramatic increase in our prison populations.

　　这项政策已经让我们监狱的囚犯人数激增。

　　The crisis has led to the closure of a number of non-essential government services.

　　危机已导致了许多可有可无的政府机构的关闭。