______describes，in detail，the project’s deliverables and the work required to create those deliverables．

A．Product scope description

B．Project objectives

C．Stakeholder Analysis

D．The project scope statement

硝酸甘油与β受体阻断药合用治疗心绞痛的理由是（）.

A．二者均可缩小心室容积 

B．二者均可降低心肌耗氧量 

C．二者均可减慢心率 

D．减少血液血管紧张素Ⅱ水平 

E．减少血液缓激肽水平