"Many kinds of animals travel great distances each year. The top traveler among these creatures is a bird called the Arctic tern. The Arctic tern spends much of its life in the pursuit of summer. In June, it can be found in the Arctic, near the North Pole. There the tern raises its young during the Arctic summer.
By August, the Arctic winter is about to begin. No matter, for the young terns are strong enough now to fly to Antarctica, near the South Pole, where summer will soon begin. The eleven-thousand-mile trip will take about thirteen weeks. That means the terms will fly more than two hundred miles a day!"
The word "pursuit" means ...
