Many children want to buy computers( 1 )they like to play computer games,（ 2 ） they don't know playing them for a long time is bad for their eyes,（ 3 ） we look around we can see many children begin to wear glasses when they are six （ 4 ） seven years old .（ 5 ） parents and teachers should tell those.children not to play at the computers for a long time .Computers are very useful（ 6 ）computer games are very interesting,（ 7 ） we should take good care of our eyes .
1．A．but B．so C．because
2．A．but B．so C．and
3．A．but B．and C．if
4．A．or B．but C．so
5．A．But B．So C．Or
6．A．but B．and C．so
7．A．and B．but C． so