语法与词汇 18.Lots of rescue workers were working around the clock, ______supplies to Yushu, Qinghai province after the earthquake.
【正确答案】 A
【答案解析】句意：地震发生后，大量的营救人员夜以继日地为青海省玉树县提供补给。此处应使用现在分词短语作伴随状语，故答案选A。