What have people discovered about hobbies
Hobbies can be profitable and ______ .

A、He went to visit his grandma in the countryside.
B、He went for a picnic with his friend in the park.
C、He stayed at home and doing nothing.
D、He climbed the mountain with his friend in the city.

A. He has just bought a brand new car.
B. He has just sold his old car.
C. He has an old Ford.
D. He borrowed a car from his cousin.