B4

Computers and microchips have become part of our everyday lives.
(present perfect, т.к. стали в прошлом и являются частью нашей жизни до сих пор.)

BECOME

B5

We read magazines which have been produced on computer, we buy things with the help of computer; we pay bills prepared by computers.
(present perfect passive,т.к. действие не заканчивается. Хотя можно использовать present simple passive, читаем журналы, которые (вообще) производятся …)

PRODUCE

B6

Just dialing a phone number involves the use of a sophisticated computer system.
(Participle I “набирая”, подходит по смысловому контексту)

DIAL

B7

In the past, life without computers was much more difficult than it is today.
(степень сравнения)

DIFFICULT

B8

The first computers were able to multiply long numbers, but they could not do anything else.
(could – прошедшее время от can)

NOT CAN

B9

Nobody believed stories about robots and space travel, but now computers are able to do almost all difficult jobs.
(past simple, никто (тогда) не верил)

BELIEVE

B10

What makes your computer such a miraculous device? It is a personal communicator that enables you to interact with other computers and with people around the world. And you can even use your PC to relax with computer games.
(3е лицо, добавляем “s")

ENABLE