Sigh, don't you believe in God? The only one that created the Earth is God but if you want a scientific explaination I can explain to you. You see, around 4.6 billion years ago, neither the Earth or any of the other planets existed.mTher was just this vast, dark, very hot cloud of gas and dust swirling around the newly formed Sun. Gradually, the cloud cooled and the gas began to condense into billions of droplets. Slowly these droplets were pulled together into clumps by their own gravity and they carried on clumping until all the planets, including the Earth, were formed. But it took another half a billion years before the earth had cooled down enough to form a solid crust with it's atmostsphere around it. That's it.
I believe it's a challenge posed to the students.  Lesson is about theory on creation :-)  Your answer is good :-)