炉前油系统为什么要装电磁速断阀？

下列属于钾肥的是（　　）

A．NH₄Cl

B．K₂CO₃

C．NH₄H₂PO₄

D．Ca₃（PO₄）₂

随着社会的发展，我国已逐步由温饱型社会进入小康型社会，小康生活进入寻常百姓家，长久以来的小康梦想，正逐步转化为现实。小康目标的实现，意味着 [ ]

①我国已实现了现代化　②物质生活得到了明显的改善　③我国贫富差距已消灭　④精神生活的日益充实

A．①②　　　　

B．③④　　　　

C．②④　　　

D．①③

关于黏液样变性，下列不正确的是（）。

A.可见分泌黏液的杯状细胞

B.细胞间质出现类黏液的聚集

C.可见急性风湿心血管壁

D.可见间叶肿瘤的间质

E.可见动脉硬化时血管壁

The ARPANET (79) ( the rules of syntax that enable computers to communicate on a network) were originally designed for openness and flexibility, not for (80) The ARPA researchers needed to share information easily, so everyone needed to be an unrestricted "insider" on the network. Although the approach was appropriate at the time, it is not one that lends itself to today’s commercial and government use.
As more locations with computers (known as (81) in Internet parlance)joined the ARPANET, the usefulness of the network grew. The ARPANET consisted primarily of university and government computers, and the applications supported on this network were simple: electronic mail ( E - mail), electronic news groups, and (82) connection to other computers. By 1971, the Internet linked about two dozen research and government sites, and researchers had begun to use it to exchange (83) not directly related to the ARPANET itself. The network was becoming an important tool for collaborative research.

A) safety B) guard C) attachmentD) security

设置有TSRS的高速铁路在下达临时限速时受令处所不需要选择相关车站。