Write questions for the following answers, as in the example:
A: Is London a city to visit?
B: Yes, it is. London is a city to visit.
A:
?
B: Yes, it is. The British Museum is the oldest museum in the world.
A:
B: No, there aren't 100 galleries in the museum. There are 90 galleries.
A:
?
B: Yes, the entrance is free.​