________ with his work in the Satellite Launch Site，he could not spare any time to stay with his parents though they are very old.

A．As occupying

B．Occupied

C．Having occupied

D．To occupy

信息技术对企业的吸引力在于它能够被用来获取竞争优势。主要体现在速度优势方面的信息技术包括（）。

A.无线通信

B.开放式系统

C.人工智能

D.电子商务