化学反应前后，下列各项一定不变的是①原子种类；②原子数目；③分子数目；④元素的化

康复工程

Traditional Internet access methods like dial-up were so slow that host computers were connected to the dial-up (1) at the customer premise over slow (2) ports. PPP was designed to run directly over these serial links. But with the advent of broadband Internet (3) technologies such as ADSL and cable modems there has been a considerable increase in the bandwidth delivered to the end users. This means that the host computers at the customer premise connect to the (4) or cable "modem" over a much faster medium such as Ethernet. It also means that multiple (5) can connect to the Internet through the same connection.

（4）应填入（）

A．FDDI

B．HDSL

C．ADSL

D．CDMA

关于围生保健以下哪项错误（）。

A.围生保健是指围绕妇女妊娠、分娩后产后阶段的保健

B.围生保健工作从妊娠20周开始

C.围生保健从围生期内开始的保健

D.妊娠全过程可分为妊娠早期、妊娠中期、妊娠晚期

E.B+C

2008—2011年内，低收入户人均纯收入与上年相比增长最快的年份是()。

A.2008年 

B.2009年 

C.2010年 

D.2011年

正常情况下，肾小管将吸收肾小球滤过液总量的多少

A．1

B．10

C．90

D．99

E．50