题目

阅读下面短文，根据短文内容完成表格中所缺信息每空一词。Your school days should be some of the best and happiest days of your life．How can you gain the most from them，and ensure that you do not waste this wonderful opportunity to learn?Be positive（积极的）at school! Don’t say things are difficult or boring. Show an interested in school life and your school subjects. Take part in lots of activities. Put up your hands quickly in class．Go round the school with a big smile．If you are not working，you are wasting your time at school. Teachers cannot make ev 对于空间三条直线，有下列四个条件： ①三条直线两两相交且不共点； ②三条直线两两平行； ③三条直线共点； ④有两条直线平行，第三条直线和这两条直线都相交． 其中，使三条直线共面的充分条件有________．