The statement $u \in A$ is true because $u$ is one of the elements in the set $A = \{u, v, y, z\}$.

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Here are 5 related questions:

1. What does it mean for an element to belong to a set?
2. How do you determine if an element is not in a set?
3. Can a set have duplicate elements?
4. How do you represent a set that has no elements?
5. What is the difference between a subset and an element of a set?

Tip: A set can contain any kind of elements, including numbers, letters, or even other sets.