—What a surprise it is that you've hiked on Mount Tai!

—I didn't believe I could do it _____ I got to the top. [ ]

A. unless

B. after

C. until

D. as

An Intranet is (71) the application of Internet technology within an internal or closed user group．Internets are company (72) and do not have a (73) connection to the Internet．Used properly an Internet is highly effective corporate tool，capable of regularly (74) information to empower the workforce with the information needed to perform their roles．Used in this way，Internet represent a step towards the (75) office．

72（）

A．common

B．shared

C．special

D．specific