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

生物体由小长大，是与        __和       __ 分不开的，但是如果仅仅由此，是无法发育成一个功能健全的生物体的，还需要进行        ____。