The essential difference between field experiments and other observational methods is that researchers have more control in field experiments.

现场实验和其他观察方法的本质区别在于，现场实验中研究人员有较大的控制权。

The essential difference between Sam and me was the fact that I took life seriously.

【essential】山姆和我之间的本质区别在于我认真对待生活。

The reason this is possible is that at the grand unification energy there is no essential difference between a quark and an antielectron.

这是可能的原因是，在大统一能量下，夸克和反电子之间没有本质区别。

They did not, perhaps, attend to the great and essential difference which nature has established between corn and almost every other sort of goods.

也许他们没有注意到大自然在谷物和几乎所有其他种类的商品之间建立的巨大而本质的区别。

How have the last few years revealed the essential differences between the democracies which have a capacity to endure and those which have not had it.

3. 过去几年如何揭示了有能力持久的民主国家和没有能力的民主国家之间的本质区别。

One study found that DNA ancestry tests reinvigorate age-old beliefs in essential racial differences, that our socially constructed racial categories like “white” or “black” are essentially different from each other.

一项研究发现， DNA 血统测试重新激发了人们对种族差异的古老信念，即我们社会构建的种族类别，如“白人”或“黑人”，在本质上是不同的。

The crises of the last few years have revealed the essential differences between the democracies which have a capacity to endure and the democracies which have not had it.

过去几年的危机揭示了具有持久能力的民主国家与没有持久能力的民主国家之间的本质区别。

Land occupied by such tenants is properly cultivated at the expense of the proprietors, as much as that occupied by slaves. There is, however, one very essential difference between them.

这些佃户占用的土地与奴隶占用的土地一样，都是以所有者的费用为代价进行适当耕种的。然而，它们之间有一个非常本质的区别。

In the different ways in which this monopoly has been exercised, consists one of the most essential differences in the policy of the different European nations with regard to their colonies.

行使这种垄断的方式不同，这是不同欧洲国家对其殖民地政策的最根本的区别之一。