How many people in the world think that the earth is flat?

I would say millions of people think the world is flat. I would guess the vast majority of indigenous peoples in say the Amazon, or parts of Africa, or many people in the Himalayas or rural India likely believe the world is flat. This isn't due to stupidity but rather a lack of education and the fact that whether the world is flat or round has no bearing on their lives. The Internet and globalization is rapidly changing this, but there are probably many more flat earthers than we often assume.

Now how many in the developed world believe the earth is flat? Hopefully a vanishingly small percentage.

probably not the "magnets"in the magnet, so to speak, are thought to be electrons orbiting in shells. vurrent loops two sides to the loop

answer;

d. are made mostly of liquid

explanation;

-the general   composition and structure planets includes; they have a thick gas and liquid layer covering a small,solid core. mostly the gases are hydrogen and helium atmosphere and layers of liquid hydrogen. for instance neptune and uranus are examples of the outer planets, they have a core covered by ice and ammonia.

-neptune's atmosphere is hydrogen and helium with a bit of methane so there is no oxygen to breath and the interior is made up of frozen water and ammonia with a rock and iron core. thus, there is no liquid water or solid surface to survive.