减少肝性脑病患者肠道有毒物质的产生，首选的抗菌药物是（） A.青霉素 B.氯霉素 C

The purpose of the requirements definition phase is to produce a clear, complete, consistent, and testable (16) of the technical requirements for the software product.
During the requirements definition phase, the requirements definition team uses an iterative process to expand a broad statement of the system requirements into a complete and detailed specification of each function that the software must perform and each _( 17) that it must meet. The starting point is usually a set of high level requirements from the (18) that describe the project or problem.
In either case, the requirements definition team formulates an overall concept for the system and then defines (19) showing how the system will be operated publishes the system and operations concept document and conducts a system concept review (SCR).
Following the SCR, the team derives (20) requirements for the system from the high level requirements and the system and operations concept. Using structured or object-oriented analysis, the team specifies the software functions and algorithms needed to satisfy each detailed requirement.

A．function

B．definition

C．specification

D．statement

A．小球一定带正电

B．qE>mg

C．小球一定带负电

D．qE<mg

已知3 个类O、P 和Q，类O 中定义了一个私有方法F1 和一个公有方法F2；类P 中定义了一个公有方法F3，类P 为类O 的派生类；类Q 为类P 的派生类，它们的继承方式如下所示： class P : public O {…}; class Q : private P {…}; 在关于类P 的描述中正确的是 （43） ；在关于类Q 的描述中正确的是 （44） 。

（43）处填（）。

A．类P 的对象可以访问F1，但不能访问F2

B．类P 的对象可以访问F2，但不能访问F1

C．类P 的对象既可以访问F1，也可以访问F2

D．类P 的对象既不能访问F1，也不能访问F2

躯体感觉包括（）

A.浅感觉，深感觉，复合感觉

B.浅感觉，深感觉，内脏感觉

C.浅感觉，深感觉，特殊感觉

D.浅感觉，复合感觉，内脏感觉

E.浅感觉，复合感觉，特殊感觉

简述电动机的冷却方式和散热原理？