Types of gravel include: 1  Bank gravel: naturally deposited gravel intermixed with sand or clay found in and next to rivers and streams. 2  Bench gravel: a bed of gravel located on the side of a valley above the present stream bottom, indicating the former location of the stream bed when it was at a higher level.
1 is the sixth part of 6. 2 is two sixths, and also the third part, of 6. 3 is three sixths, and also half of 6. 4 is four sixths, and also two thirds, of 6. is the sixth part of 6. 2 is two sixths, and also the third part, of 6. 3 is three sixths, and also half of 6. 4 is four sixths, and also two thirds, of 6.
So three plus one is equal to four and we get an HDI equal to four, right? Up here we had one ring and we had an HDI equal to one. Up here we had one double bond and an HDI equal to one. We could also calculate the HDI using a formula. So we could write that the hydrogen deficiency index is equal to one-half times what's in the parenthesis.