用所给词的适当形式填空

①To make a sandwich, we need two (slice) of bread, some vegetables and some meat.

② It rained hard yesterday, but (luck) we brought our raincoats and didn't get wet.

③Ted told us an unusual story (call)Mystery steps.

④ Cindy had fun (make) flashcards with her cousin.

⑤ How old was Laura when she became a (skate) champion?