Instruct: Classify a given Amazon review as either positive or negative.
Query: Served well as first sippy cup

This has served us well as my daughter's first sippy cup. It took her a while to get used to sucking on it (and we helped by taking out the insert at first), but she's now excellent at it. My only complaint is that it turns moldy so quickly. We wash it and dry it every night, but black mold has forced us to throw it away sooner than we would like.