A mango tree is mentioned so I would say a mango
The supporting sentence that makes use of an example is:
Beto used interval training to prepare for and win a marathon.
In this excerpt, the first sentence is the <em>topic sentence</em>, which is the sentence that contains the main idea. The second sentence is the supporting sentence that gives the reader further information about the topic. In the third sentence, the writer gives a specific example to support the main idea. Finally, in the last sentence, the writer provides factual information to make the topic sentence more relevant.
Allusion is a figure of speech, in which one refers covertly or indirectly to an object or circumstance from an external context. For example, you might say to one of your guy friends, "Don't act like Romeo in front of her." that would mean you are referencing to Shakespeare's "Romeo and Juliet."