Why is this verse an example of iambic pentameter

an explanatory essay explains something and an argumentative essay argues for or against something. hope this : )

nilanjana sudeshna "jhumpa" lahiri, is an american writer and professor who has received several awards from the early 2000s, such as pullitzer price for fiction in 2000. she normally writes about her experienced in a cross-cultural environment, as she relates to her experiences growing upin america from indian immigrants.

once upon a time, belongs to a series of short stories divided in two parts, named "unaccostumed to earth", being this the first short story of the second part. this second part focuses in the story of two people, who after briefly sharing their childhood they meet again and despite their completely different lifestyles, they find a strong connection.