今天我们要学的词是volunteer。 Volunteer, 是义务工作者、志愿者的意思。"We need some volunteers to organize the event," 我们需要一些义务工作者，帮助组织这次活动。"She has been doing a lot of volunteer work since her retirement," 她退休后从事了很多义务工作。星期二地球日Earth Day。"During the weekend, volunteers around the country took part in various activities to clean up the environment," 美国全国各地的义务工作者利用周末的时间参加各种清理环境的活动。好的，今天我们学习的词是volunteer...