Who makes up most of the work force in the food service industry

The caves at lascaux were closed in 1963 because a. vandals were destroying the paintings b. the collective breath of the many visitors caused the paintings to corrode c. the weather was destroying the paintings d. the government of france wanted scholars to be able to study the work without distraction

Ineed someone to describe what they mean in the instructions !

What are you doing this summer? fr !