A pull-down menu that can be moved from the place where it was first displayed to another part of the screen that may be more convenient, and from where any of its options may be selected at a later time.
科学参考收录了60776条科技类词条，基本涵盖了常见科技类参考文献及英语词汇的翻译，是科学学习和研究的有利工具。