to be was/were been
to have had had
to mean meant meant
to learn learnt learnt
to become became become
to bring brought brought
to know knew known
to think thought thought
to buy bought bought
to play played played
to take took taken
to do did done
to begin began begun
to give gave given
to make made made
to keep kept kept
to get got got
to read read read
to show showed shown
1.Many people had an opportunity to use computers
2.There was no doubt that computers were solving so problems very quickly
3.Instructions directed the operation of a computer