信息系统的开发应有专门的研制开发队伍，组成这支队伍的方式一般有四种，我们提倡的是

A．联合开发型

B．顾问开发型

C．自行开发型

D．委托承包型

It was with great joy        he received the news that his lost daughter had been found.     [ ]

A. because                    

B. which      

C. since                      

D. that