They were unsure about the contract's legality.这份合同是否具有合法性，他们心里没底。

We questioned the legality [=lawfulness] of the testing.我们质疑测试的合法性。

We discussed the complex legalities involved in buying and selling a home.我们讨论了涉及房屋买卖在法律上应遵守的复杂细节。