他们正在对新药进行临床试验。

They are conducting a clinical ___trial on a new drug.

他们雇用她为期六个月的试用期。

They've employed her for a six-month ___trial period.

目前我们有一个特别优惠，即免费三个月的试用期，这样你可以了解俱乐部如何运作。

At the moment we have a special offer which is a free three-month ___trial period, so you can have an idea of how the Club works.