Simplify the following text for a Grade 10 native English-speaking person.
Original: Although the author speaks of the mythological Fu Xi , a passage of his writing gives hint that the water wheel was in widespread use by the 1st century AD in China ( Wade-Giles spelling ) :
Simplified: Although the author speaks of the mythological Fu Xi , a passage of his writing gives hint that the waterwheel was in widespread use by the 1st century AD in China .