这场免费参加的培训活动将于3月19–21日举行，并提供二氧化碳（R744）和丙烷（R290）系统的实操体验。
【英文原文】
原标题：NASRC to Host Natural Refrigerant Training Summit in Pittsburgh
The free-to-attend training event will take place March 19–21 and offer hands-on experience with CO2 and propane systems.
