In this group exercise class at one of the Washington Sports Club's locations in Washington D.C., riders spin their bikes faster and faster following the instructor's command. 

Jillian Cooney, who has been a member of this sports club for 4 years, enjoys the spinning class. But these days, she says, the group exercise is a little different. 

"_________________________________. I would necessarily say it's more difficult, more challenging. I challenge myself more with these levels than when I use the resistance." 

The sports club's stationary cycles were recently retrofitted with so-called "Green Revolution" technology, which turns every bike into an electrical generator. _________________________________. 

Mike Curnyn is with the Green Revolution, a company based in the eastern U.S. state of Connecticut. "We put a generator on each bike in the group cycling studio so while the fitness enthusiasts are getting their workout, their energy is being captured and being converted to clean electricity _________________________________."

答案：

(1)I think it was more challenging
(2)The technology allows riders to generate power with every turn of the pedals
(3)that's being used to help power the health club