分析课文句子中的-ing属于什么用法: Having collected and evaluated the information, I help other scientists to predict where lava from the volcano will flow next and how fast. 收集和评估这些信息之后,我就帮助其他科学家一起预测火山喷发的熔岩接着将往何处流,流速是多少。
Leading-in
Having collected and evaluated the information为 -ing构成的现在分词的完成式, 在句中作时间状语,相当于after引导的时间状语从句。