Mark, however, needs to travel extensively with his varied business interests.

然而，马克因各种各样的商业利益而需要四处旅行。

All these issues have been extensively researched in recent years.

所有这些问题近年来都已得到广泛的研究。

Hydrogen is used extensively in industry for the production of ammonia.

在工业中氢气被大量地用于氨的生产。