They are said () each other long time before they met in Harvard University where they worked together on a research project.

A. to know

B. to have known

C. knowing

D. having known

Java 解释器采用生成与体系结构无关的 【11】 指令的技术，只需安装Java 运行系统，就可保证Java 程序在网络的任何地方运行。