He likes （helping old people） on the buses.对加括号的部分提问 _____ ______ he like ______?

He likes （helping old people） on the buses.对加括号的部分提问 _____ ______ he like ______?
He likes （helping old people） on the buses.对加括号的部分提问 _____ ______ he like ______?

He likes （helping old people） on the buses.对加括号的部分提问 _____ ______ he like ______?
What does he like doing?

__What___ ____does__ he like __doing____？

What does he like doing？