Question

In 20 th century,_______ were invented - 1 ) electric trains 2) supersonic aeroplanes 3) monorail 4) All of these

Answer 1

dear friends,
in 20th century , _______were invented
all of these .
HOPE IT WILL HELP YOU
plzz mark me as brain list
THANKS

Answer 2

Answer:

monorail was invented in 20th century