今天我们要学的词是 on the sidelines. On the sidelines 在外围。Syria was a major topic for discussion on the sidelines of the G-20 summit. 叙利亚是G20峰会外围会谈的主要话题。U.S. President Barack Obama and Russian President Vladimir Putin met on the sidelines of the G-20 summit, but failed to reach a deal to end the violence in Syria. 美国总统奥巴马和俄罗斯总统普京在G20峰会外围举行会谈，未能就结束叙利亚暴力冲突达成协议。好的，我们今天学习的词是 on the sidelines, on the sidelines, on the sidelines...