对关系S和R进行集合运算，结果中既包含S中的所有元组也包含R中的所有元组，这样的集合

慢性肾炎的治疗，主要目的是

A．防止高血压脑病

B．防止心脑血管并发症

C．消除蛋白尿、血尿

D．防止腹腔积液

E．防止或延缓肾功能的进行性减退

工作面用液压支架支护时，支架要排成一条直线，其偏差不得超过（）mm。

A、±50

B、＋50

C、±100

D、＋100

阻塞性睡眠呼吸暂停综合征须与下列哪些疾病鉴别（）

A.上气道阻力综合征

B.发作性睡病

C.慢性喉炎

D.原发性鼾症

E.COPD

The approach we propose is a system-oriented methodology for knowledge acquisition, this orientation emphasizes ongoing documentation throughout each cycle and technique applied. Program-wide documentation is suggested, both for the purpose of internal (91) and for later verification and (92) efforts. The documentation system we propose includes a central "knowledge acquisition (93) " which is (94) to reflect knowledge acquisition plans, session nodes, and domain expert participation. Specifically, (95) within the database system include knowledge acquisition forms, which document plans for, and notes from, knowledge acquisition session, domain expert file, and rule content forms.

A. validation B. confirm
C. effection D. evaluation

燥痰的特点是（）

A.痰白清稀或有灰白点

B.痰黄黏稠有块

C.痰少而黏，难咯

D.脓血痰味腥臭

E.痰白滑量多，易咯