Fill in the blank with an appropriate option.

Do you ______ your tap water before drinking?

filter

The correct answer is filter.

The word filter means to remove impurities from something. In this sentence, the speaker is asking if you remove impurities from your tap water before drinking it.

The options flush, flirt, and flicker are not as appropriate because they do not have the same meaning as filter. For example, the option flush means to rinse something with water, but this is not the same as removing impurities from something. The option flirt means to behave in a way that suggests a playful romantic interest in someone, but this is not the same as removing impurities from something. The option flicker means to move or shine with a sudden, brief, unsteady light, but this is not the same as removing impurities from something.