carefullyifanychangeoccurswhendoingexperimentsint... 国语站 题库 2.19W 大中小设置文字大小 问题详情: carefully if any change occurs when doing experiments in the lab.A. Observe B. To observe C. Observed D. Observing【回答】A知识点:祈使句 感叹句题型:选择题 TAG标签:#