Air horn.
Not yet unless they have been invented by millionaires and not spread out to the rest of the world
it hasn't been invented yet.
Yes, the egg cracker has been invented.
What hasn't been invented is a flying car!
YES it has been invented
Bionic eyes have not been invented yet.
Umm it really as not been invented yet so... I can not really say yet
There are so many things that people of the past have dreamed of but never invented any failed invention is a thought of the past that hasn't been invented yet.
something that hasn't been invented yet is a teleportation device Manned Interstellar Travel
The aeroplane has not been invented yet.
No, it had not been invented yet.
Cell pphones have not been invented yet but cell phones have.