Both husband & wife receive 1099s for sales. (Wife is full-time; husband helps out 3-4 times/year at big events.) Can we combine or must we complete two Schedule C's?

Each are paid separately when they have a sale, and each receives a separate 1099, but husband's is less than $1000.  He has almost no expenses (a little mileage) so it would be easier to combine both into one Schedule C if possible.