Choose the appropriate variant. My aunt is a nurse. She _______ wear a uniform at work.

The correct answer is "has to". Here's why: * The sentence expresses an obligation or necessity. Nurses are generally required to wear uniforms. * "Has to" expresses this requirement. Therefore, the completed sentence is: "My aunt is a nurse. She has to wear a uniform at work." Let's review why the other options are incorrect: * **Mustn't**: means "must not" and expresses prohibition. This doesn't make sense, as nurses are typically *required* to wear uniforms, not prohibited. * **Needn't**: means "doesn't need to" and expresses lack of necessity. While perhaps some nurses are *not required* to wear a uniform, the context of the sentence implies obligation. * **Doesn't have to**: Also expresses a lack of necessity, similar to "needn't". It's not the best fit for a general statement about nurses.