What happens to the mass of bread when it is left for 5 days and it goes hard? explain.

Since the bread becomes hard in the span of few days, the bread is now dehydrated. The absence of moisture in the bread will affect its mass negatively therefore the mass fo the bread will decrease albeit in a very small proportion only. 

  a. chromosomes are duplicated before cell division so that each new daughter cell has a complete set

Ibelieve the answer is relative humidity  because it makes more sense that way. solar flares usually occur in space it doesn't affect the earth, well it could but it wont make a significant damage.  latitude is land it doesnt do anything. prevailing winds, i dont know the correct meaning for this but i doubt that affects the land so it has to be relative humidity.