Connecting patches and adding differently sized holes to a model are also highly nontrivial problems that are all addressed in the paper.

给模型连接不同的片和添加不同大小的洞状结构同样是非常不简单的问题，这些也都在文中有所阐释。

Yet in developed countries a large proportion of people have a nontrivial amount of discretionary income to play with.

然而，在发达国家，很大一部分人拥有大量可自由支配的收入。