Write SQL statements for the following:

1. For each store, give the stores name and the name of the most expensive pizza sold in it.

2. Find the names of the stores that sell all pizzas.

3. Find the codes of pizzas that are sold in all stores.

Where the relations are as follows:

PIZZA (code, name, size) STORE (name, area, phone) SELLS (store_name, code, price)

Many thanks in advance and have a great day.