Input: On his return to Nuremberg in 1495, Durer opened his own workshop (being married was a requirement for this). Over the next five years his style increasingly integrated Italian influences into underlying Northern forms. Durer's father died in 1502, and his mother died in 1513. His best works in the first years of the workshop were his woodcut prints, mostly religious, but including secular scenes such as The Men's Bath House (ca. 1496). These were larger and more finely cut than the great majority of German woodcuts hitherto, and far more complex and balanced in composition. It is now thought unlikely that Durer cut any of the woodblocks himself; this task would have been performed by a specialist craftsman. However, his training in Wolgemut's studio, which made many carved and painted altarpieces and both designed and cut woodblocks for woodcut, evidently gave him great understanding of what the technique could be made to produce, and how to work with block cutters. Durer either drew his design directly onto the woodblock itself, or glued a paper drawing to the block. Either way, his drawings were destroyed during the cutting of the block. 
"How long after opening his workshop did Durer's mother die?" is "17"?
Output: no
Input: Relying on an animal to come by is risky. A flower may have to wait a long time for the right animals to come by. What if one never passes close enough to the flower? Hoping the wind will blow is also risky for a plant. What if the wind does not blow? What if the blowing pollen does not land on another flower? The wind could even blow the pollen over the ocean where it is wasted. Giving free nectar is costly. It is not a good use of the plants energy. A plant uses a lot of energy to produce nectar. Some animals may just drink the nectar. They may not carry off any pollen in return. To improve their chances, plants evolved special traits. For example, they developed ways to hide their nectar. Only certain animals were able to get at the plants hidden nectar. These specific animals might be more likely to visit only flowers of the same species. This was also a benefit for some animals. Animals also evolved special traits to get to the nectar. 
"Why is it risky for a flower to wait on an animal to come by?" is "They may just drink the nectar"?
Output: yes
Input:  We were cornered in a sort of way already.  But these butchers up the cavern had been surprised, they were probably scared, and they had no special weapons, only those little hatchets of theirs.  And that way lay escape.  Their sturdy little forms--ever so much shorter and thicker than the mooncalf herds--were scattered up the slope in a way that was eloquent of indecision.  I had the moral advantage of a mad bull in a street.  But for all that, there seemed a tremendous crowd of them.  Very probably there was.  Those Selenites down the cleft had certainly some infernally long spears.  It might be they had other surprises for us.... But, confound it!  if we charged up the cave we should let them up behind us, and if we didn't those little brutes up the cave would probably get reinforced.  Heaven alone knew what tremendous engines of warfare--guns, bombs, terrestrial torpedoes--this unknown world below our feet, this vaster world of which we had only pricked the outer cuticle, might not presently send up to our destruction.  It became clear the only thing to do was to charge!  It became clearer as the legs of a number of fresh Selenites appeared running down the cavern towards us. 
"What are two reasons that the narrator decides the only option is to charge?" is "Danger above"?
Output:
no