对混凝土枕线路，当450＜R≤600时（钢轨为12.5m/根）应安装轨距杆（）根。

论述使用发酵剂的目的。

男性，64岁。近1年来每天午睡或夜间22点发生胸骨后压迫性疼痛，每次持续10分钟，坐起或含硝酸甘油3分钟缓解。

最可能的诊断是（）.

A.初发型心绞痛

B.劳累型心绞痛

C.卧位型心绞痛

D.变异性心绞痛

E.梗死前心绞痛

In project management , a (73) is a listing of a project’s milestones, activities, and deliverables, usually with intended start and finish dates. Those items are often estimated in terms of resource (74) ,budget and duration, linked by dependencies and scheduled events.

A. schedule

B. activity

C. plan

D. contractor

肚拉功效与作用

电镀（铸）法