眼球突出，眼眶容积减少的原因包括()

A．颅面骨发育不全(如Crouzow综合征致颧骨、上颌骨发育不良)

B．眶骨及骨膜的炎症

C．眶内肿瘤

D．眶骨骨膜下出血

E．因骨折眶骨板向内移位

Many of the activities performed during the preliminary investigation are still being conducted in (1)， but in much greater depth than before. During this phase, the analyst must become fully aware of the (2) and must develop enough knowledge about the (3) and the existing systems to enable an effective solution to be proposed and implemented. Besides the (4) for process and data of current system, the deliverable from this phase also includes the (5) fortheproposedsystem.

空白（5）处应选择（）

A.hardware and software specification 

B.system performance specification 

C.formal requirements definition 

D.general problem statement