2. cellulosic biofuels are fuels that are produced by fermentation of cellulose containing materials (wood, leaves, paper, etc.) by yeast. what would be necessary before yeast cells are capable of fermenting sugars from cellulose? (hint: consider the similarities between lactose and cellulose? )

The answer is hydrolysis. This can be achieved through the use of a strong acid or cellulolytic enzymes (from fungi) that are capable of converting the cellulose to fermentable sugars.  This pretreatment hydrolyzes the β-1, 4-glycosidic linkages of cellulose subunits.

the correct answer is - d. china has a large and growing population.

the fact that china has a large (the biggest) population, and it is still growing, doesn't hinder the agriculture production in the country. in fact, it can for increased production in the agriculture, since there's more labor force, as well the sheer mass of people produces lots of scientists that come up with new inventions as to how to improve this sector. nice example is the inner mongolia region in china, in general dominated by the gobi desert, but few scientist came up with a nice idea as to how to make the region productive by using plants that are very resistant to droughts, so lots of people have been employed, and the region is becoming greener and greener each year, and the production of food in this region is also increasing.