One reason, there a shortage of producers in a food web. As a result, the number of deer and wolves decreased. The reason that both deer wolf population declined is that

i believe it is 40–40–20%

explanation:

c. heat could easily travel through the molecules in the air and escape/enter the flask. removing the air slows down the heat transfer.  

for step 7 table c on the lab "newtons law of action"   the average time it took the car to travel .25 meters   was 1.92 seconds.

the average time it took the car to travel 0.50 meters was 2.61 seconds

hope this : )