Question

Вставить слова в скобках в нужной форме..
the world’s first electronic computer (1) (build) at the university of
pennsylvania in 1946, although computer-like machines (2) (invent) much
earlier.
computers (3) (sell) commercially for the first time in the 1950s, and a lot of
progress (4) (make) since then. computers are now much smaller and more
powerful and they can (5) (buy) much more cheaply.
computers (6) (apply) in many fields – in business, science, medicine and
education, for example. they can (7) (use) to forecast the weather or control
robots which make cars. the computer’s memory is the place where information (8)
(keep) and calculations (9)
(do).
a computer cannot think for itself – it must (10) (tell) what to do. a lot of
difficult calculations can (11) (do) very quickly on a computer.
and computers (12) never (mistake).
stories (13) sometimes (hear) about computers paying people too much
money or sending them bills for things they didn’t buy. these mistakes (14)
(make) by the programmers – the people who give the computer its
instructions. some years ago a computer-controlled rocket belonging to the usa went out of
control and had to (15) (destroy). the accident (16)
(cause) by a small mistake in one line of the programme. this mistake cost the usa $18 million.
criminals have found out that computer crimes are often a lot easier than robbing banks.
hundreds of millions of dollars (17)
(steal) from american businesses every year by people changing the
information in computers.
large numbers of home computers (18) (sell) recently, especially in the
usa and britain. people know more about computers than they used to, and computers are
playing a bigger part in our lives. progress (19) ) all the time
nowadays.
it (20) (believe) we can look forward to the day when even our household
jobs like cleaning (21) (do) by computer-controlled robots.

Answer 1

1.was built 2.had been invented 3.were sold 4.has been made 5. be bought 6.are applied 7. be used 8.is kept 9.are done 10.be told 11.be done 12.have been mistaken 13.are heard 14.are made 15.be destroyed 16.was caused 17.are stolen 18.have been sold 19.is being made 20.is believed 21.will be done