We know a computer is a machine that processes data(stored in main memory)into information, under control of a stored program. We also know that, internally, a computer is a binary machine; thus the data and the program instruictions must be stored in binary form. Characters are represented in(71). Numbers are stored as binary numbers, with each bit's positional value significant. A computer's main memory is divided into bytes, words or both(depending on the system), and each of these basic storage units is assigned an(72). Using this address, the processor can read or write selected bytes or words.

The processor consists of a clock, an instruction control unit, an arithmetic and logic unit, and registers. Once a program is stored in main memory, the processor can begin to execute it. During(73), the instruction control unit fetches an instruction from main memory; during(74), the arithmetic and logic unit executes it. Precisely timed electronic pulses generated by the clock drive this basic(75)

A．a binary code

B．words

C．registers

D．positional values

[试题]We know that we are getting even older，and that the______(near)a society approximates to zero population growth，the older its population is likely to be.

[主观题]We often use the machine for making bicycles．(改为被动语态）The machine__________ often__________ for making bicycles by us．

[单选题]F．rom this passage we know that ______.A． every American cannot have gunsB． only soldiers and police can have gunsC． every American citizen can own gunsD． teachers have no money to buy guns

[单选题]A．ccording to the passage we know ______________ .A． Jack Scott asked Mr. Green not to fly to LondonB． Mr. Green would take control of a plane by forceC． The policemen mistook what Mr. Green said

[单选题]F．rom the passage, we know that __________.A． there was not enough food in Ilan long agoB． leftovers can’t be used to cook delicious foodC． zao bing is a famous dish without any fat in itD． the writer is interested in very big banquets

[单选题]Thesurvivalofcivilizationasweknowitis_____threat.(A)within(C)towards(B)under(D)upon

[单选题]Thesurvivalofcivilizationasweknowitis_____threat.(A)within(C)towards(B)under(D)upon

[单选题]F．rom the passage, we know that The song Auld Lang Syne mainly played in the USA _A． On New Year’s Eve. B. On Christmas Eve. C. On weekends. D. On holidays.

[单选题]F．rom the last paragraph we know that in Brazil______.A． it is important to arrive at the appointed timeB． it is rude for professors to be late for classC． it is normal for students to leave during lecturesD． it is natural to keep the professor stayi

[单选题]F．rom this passage we know that______.A． every American cannot have guns.B． only soldiers and police can have guns.C． every American citizen can own guns.D． teachers have no money to buy guns.