The years are
a 1
b 5
c 8
d 6

a time line cause it goes from 685 to 978

sorry, is there a picture? i do not see any arrows.

wut? unius0123 wut?

answer: zinc is the substance which has a volume of 1.38 .

density is defined as the mass of an object per unit volume.

it can be calculated by dividing mass of a substance by its volume i.e.

si unit of density is kg per cubic meter and cgs unit of the same is gram per cubic centimeter.

now from the given data volume can be calculated by the formula .

hence, the volume of aluminium will be = which comes out to be 1.703 .

similarly, volume of zinc, chromium, and nickel will be 1.378 , 0.869 , and 0.356 respectively.

some inherited genetic mutations can be good for the offspring, so the answer is different genetic mutations cause many forms of cancer.