试卷5

通信英语强化训练试题（五）

Ⅰ单项选择题：(Choose the best one)

( )1.The telephone contains a transmitter and receiver for _________back and forth _________analog voice and analog electrical signals.

A. convert, in

B. converting, between

C. conversion, to

D. converted, into

( )2.Each subscriber connects _________local loop to a switching center, _________as an end office.

A. to, calling

B. with, known

C. the, know

D. via, known

( )3.The trunks are designed _________multiple voice-frequency circuits _________either FDM or synchronous TDM.

A. carry, use

B. carried, used

C. to carry, to use

D. to carry, using

( )4.Although originally to service analog telephone subscribers, the telephone network handles substantial data traffic _________modem, and gradually being

converted to a digital network.

A. implemented, via

B. implementing, in

C. to implement, within

D. design, on

( )5.Designers have found it convenient _________these nodes into a hierarchy or tree topology, _________five classes of switching centers or nodes.

A. organization, consist

B. organize, consisting

C. to organize, consisting of

D. organizing, to consist

( )6.ISDN’S enormous importance is only gradually being _________. Years of work have been _________by the CCITT and the ISO.

A. understand, carry

B. understanded, carried

C. to be understood, to carry

D. understood, carried out

( )7.The term ISDN was first defined within the CCITT in 1972. It referred to a network _________end-to-end digital connectivity _________a range of services.

A. providing, for

B. provision, to

C. provided, with

D. provide, into

( )8.Similarly, the introduction of voice encoding techniques _________pulse code modulation contributed _________the ISDN’s concept evolution .

A. usage, on

B. using, to

C. use, with

D. used, so as to

( )9.In fact, ISDN _________conceived a quarter of a century ago and is only now _________to reach maturity.

A. is, begin

B. was, beginning

C. be, to begin

D. will be, began

( )10.The enhanced quality is achieved when a signal is digitally encoded _________degradation _________the transmission medium.

A. overcome, to

B. overcame, with

C. overcoming, over

D. to overcome, due to

( )11.As regards economy, early studies suggested that digital services _________significant advantages since a substantial quantity of interface

equipment in the telephone exchange could _________.

A. offered, be eliminated

B. offer, eliminate

C. offers, is eliminated

D. to offer, to eliminate

( )puter data _________in the public domain by a packet switched data network _________X. 25 protocols.

A. are transported, based on

B. transports, base on

C. transported, based on

D. to transport, base

( )13.When _________the future BISDN network, one must _________all possible existing and future services.

A. design, take

B. designing, take into account

C. designed, account

D. to design, taking

( )14. A telex network _________telex information, i.e. messages of characters, _________at very low speed.

A. transports, transported

B. transported, transport

C. to transport, to transport

D. transporting

( )15.The N-ISDN cannot transport TV signals _________its limited bandwidth capabilities, so a special TV network is still _________.

A. because, require

B. with, to require

C. due to, required

D. within, requiring

( )16.Each network is only capable _________one specific service for _________it was intentionally designed.

A. of transporting, which

B. transporting, one

C. transport, where

D. to transport, when

Ⅱ短语英译汉：(Translate the following phrases into Chinese)

1.full-duplex connection

2.the function of concentrating traffic

3.the switching nodes called tandem switches

4. a fraction of subscribers

5.the interface between the station and the network