insert two dashes where needed.\nwhen cross-country skiers legs aching\nand lungs burning cross the finish…

insert two dashes where needed.\nwhen cross-country skiers legs aching\nand lungs burning cross the finish line of\na race, they often collapse like rag dolls.
Answer
Explanation:
Step1: Identify the first place for dashes
We need to set off the descriptive phrase "legs aching and lungs burning" from the main clause. So after "skiers", we insert two dashes.
Step2: Identify the second place for dashes
After the descriptive phrase "legs aching and lungs burning", we insert two dashes to close the parenthetical-like phrase.
Answer:
When cross - country skiers -- legs aching and lungs burning -- cross the finish line of a race, they often collapse like rag dolls.