they表示的是复数，they后动词不能加s；
they：pron.他们；她们；它们 扩展资料
They are campaigning to save the area from building development.
他们正开展一场反对在这个地区进行房地产开发的运动。
Cars are checked as they come off the production line.
汽车下了生产线立即进行校验。
They agglomerated many small pieces of research into a single large study.
他们把许多小的研究课题汇集成一个大项目。
