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.
They are an important investment by the tree and may be thorny or contain phytoliths, lignins, tannins or poisons to discourage herbivory. Trees have evolved leaves in a wide range of shapes and sizes, in response to environmental pressures including climate and predation.