对于事业单位的各项收入应该如何确认？

Frame Relay is simplified form of (51) , similar in principle to (52) , in which synchronous, frames of data are routed to different destinations depending on header information.
Packets are routed throught one or more Virtual Circuits known as (53) . Most Virtual Circuits are (54) , which means that the network provider sets up all DLCI connections at subscription time. (55) are also part of the Frame Relay specification. They privide a link that only lasts only as long as the session.

A．X.21

B．X.25

C．X.28

D．X.29

--- Could you tell us ______ ?    

--- About two weeks.  

A．how often are you going to be away

B．how often we are going to be away

C．how long are we going to be away

D．how long we are going to be away

开放性骨折体温升高时应考虑有（）

A.疼痛刺激

B.感染

C.休克

D.失血

E.组织液丢失

简述轴承流体动压润滑的机理。

下图是甲状腺活动的调节示意图（X、Y、Z表示器官，a、b表示激素）。请据图回答有关问题：

X、Y分泌的激素a、b，不仅能促进甲状腺激素的分泌，而且X、Y的分泌活动也会受到甲状腺激素含量的影响，这种调节方式被称为（）。