costly中等

prove too costly to be implemented.

实施成本过高。

The idea that one might burn down an entire house just to reclaim the nails underlines how scarce, costly and valuable the simple-seeming technology was.

人们会为了回收钉子而烧掉整座房子，这一做法凸显了这项看似简单的技术在当时是多么稀缺、昂贵和宝贵。

will be too costly to put into practice.

实施起来成本太高。

our reliance on the Internet will be costly.

我们对互联网的依赖将代价高昂。

costly.

代价高昂

Because employment protection laws make it costlier to fire an employee, employers are more cautious about hiring new staff.

由于就业保护法使解雇员工的成本更高，雇主在招聘新员工时更加谨慎。