Since they can and do successfully inter-breed, they cannot be classed as different species.
既然它们能够而且确实可以成功杂交繁殖,它们就不能被归为不同的物种。
People cannot shoot animals here, but they can only shoot pictures.
人们不能在这里射杀动物,但他们可以给动物拍照。
We cannot measure pain directly. It can only be estimated.
我们无法直接测量疼痛的程度,只能估计。
You may have heard this expression: You can lead a horse to water, but you cannot make him drink.
VOA: special.2009.07.12
iterature cannot merely be received as a definite unit of referential meaning that can be decoded without leaving a residue.
文学不能仅仅以一个确切的参考性意思的单位来理解,这种参考性意思的单位在破解时不会留下任何残余。
We cannot do anything about protons, they are buried in the nucleus, but we can add or subtract electrons.
我们不能改变质子,它们埋藏在原子核内,但是我们能够增加或减少电子。
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