will yeast ferment different kinds of sugar, such as fructose in fruit juice or lactose in milk?

Answer 1

This article says yeast can't ferment lactose:

http://faculty.mansfield.edu/bganong/biochemistry/disachyd.htm

And this article says they can ferment fructose and some others -- "They will ferment out the four monosaccharides glucose, fructose, mannose, and galactose, the disaccharides sucrose and maltose, xylulose, the trisaccharide maltotriose, and partially ferment the trisaccharide raffinose. They do not ferment melibiose or lactose."

http://members.tripod.com/~mksgrist/_vti_hbart/yeast.html