常用的烧杯有（）等三种。A、底型、高型和三角烧杯 B、低型、高型和六角烧杯 C、低型

下列何者基差之变化，称为基差走弱（）。

A.-5～-6

B.-4～-6

C.5～-3

D.5～-5

下列有关我国古代区域经济的表述，不正确的是                                    （   ）

A．区域经济管理政策直接影响了地区经济的发展

B．分裂时期的经济发展往往为统一局面提供经济基础

C．各地区经济发展的不平衡往往在统一时期得到弥补

D．王朝的首都以及少数重镇具有优先的经济发展机会

简述党管武装原则的基本含义。

A transport layer protocol usually has several responsibilties. One is to create a process-to-process communication UDP uses （1）numbers to accomplish this. Another responsibility is to provide control mechanisms at the transport level UDP does this task at a very minimal level. There is no flow control mechanism and there is no （2）for received packet. UDP, however, does provide error control to some extent. If UDP detects an error in the received packet, it will silently drop it.

The transport layer also provides a connection mechanism for the processes. The （3）must be able to send streams of data to the transport layer. It is the responsibility of the transport layer at（4）station to make the connection with the receiver chop the stream into transportable units, number them, and send them one by one. it is the responsibility of the transport layer at the receiving end to wait until all the different units belonging to the same process have arrived, check and pass those that are （5） free, and deliver them to the receiving process as a stream.

（1）是（）

A.hop

B.port

C.route

D.packet

YJ19平准器通过增减前劈刀盘与其固定盘之间的多层垫片，使前劈刀盘高于后劈刀盘（）mm，并使前劈刀盘高于后劈刀盘凹槽对准，紧固螺母。

A.0.07

B.0.1

C.0.17

D.0.2