The study tracked the patients over the course of five years.这项研究对病人进行了为期五年的跟踪调查。The latest tracking poll shows the Democrats leading by four percentage points.最新跟踪调查显示,民主党领先四个百分点。The children who are part of the study will be monitored through their school years and beyond.参加这项研究的孩子在上学阶段以及之后将被跟踪调查。