You can choose from in-person surveys (one-on-one interviews carried out at high-traffic locations), telephone surveys (less expensive than one-to-one interviews), mail surveys (easy to reach a large audience) and online surveys (simple and inexpensive way to collect data, though not reliable).
A binary tree of depth d is an almost complete binary tree if: 1  Each leaf in the tree is either at level d or at level d â 1. 2  For any node nd in the tree with a right descendant at level d, all the left descendants of nd that are leaves are also at level d.
Leaves are the part of the crown of a tree. They are the part of the tree that converts energy into food (sugar). Leaves are the food factories of a tree. They contain a very special substance called chlorophyll -- it is chlorophyll that gives leaves their green colour.