Relative clauses 2

Complete the sentences in the fact file about robots with who , which or that . Add ( x ) to show that the relative pronoun can be omitted .

Robots - the essential facts !

The word robot was first used in 1920 in a play by the Czech writer Karel ? apek , ____________________ wrote science fiction . It comes from robota , a Czech word ____________________ means 'hard work' .

The first robot ____________________ you could programme to perform useful tasks was Unimate , ____________________ was invented by George Devol in 1954 . He sold it to General Motors , an American car company ____________________ used the robot to lift hot pieces of metal .

In the 1990s , robots started exploring dangerous places . A robot called Dante , ____________________ was controlled by experts in the United States , went inside the Erebus volcano in Antarctica ; and the Sojourner rover , ____________________ was designed by the National Aeronautics and Space Administration ( NASA ) , went to Mars .

The Roomba is the first really successful robotic vacuum cleaner . Its makers have sold over eight million of them . People ____________________ know ____________________ hate doing housework just love this machine .

In 2012 , a robot ____________________ was able to move its arms , hands and fingers in exactly the same way as a human became the first robot in space . The 'robonaut' , ____________________ was developed by NASA , can perform dangerous tasks ____________________ people can't do .