Ответ:

Who /singer/ ( Меняем на sings ) in Coldplay?

Chris Martin sings in Coldplay

How old / ( Меняем на is ) Dr Who?

He is around 900 years old.

How many legs / ( has ) a spider?

A spider has got 8 legs.

When is (the)/ next Football World Cup?

The next Football World Cup would be in China, 2021

Where ( is ) / Bart Simpson from?

He is from the Simpsons TV show.

What / ( Is) Facebook?

It is an online platform.