Final answer:
Marco has chosen an important issue as his topic, specifically the decline of the bee population worldwide. This topic falls under the subject of Biology.
Step-by-step explanation:
Marco has chosen an important issue as his topic, specifically the decline of the bee population worldwide. This topic falls under the subject of Biology. Marco's informative address aims to shed light on the alarming decrease in bee numbers, which has significant consequences for the ecosystem and food production.
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