Rockets were first used in war in ______ .

A.the parents missed out on their own education when they were young.
B.it is their responsibility to help their children.
C.their children are cleverer than they were.
D.they don’t want them to go to the rural areas.

A.used to be a country of a violent society
B.used to be a country of a peaceful society
C.becomes a country of an advanced society
D.becomes a country of a decayed society