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.
Botanists and foresters have developed terms for these patterns and shapes which help in tree identification. Some tree species make things more interesting by displaying more than one type of leaf structure. Other tree species leaves make it nearly impossible to misidentify because each leaf is so unique. Trees with unique leaves include ginkgo, sassafras, yellow poplar and mulberry.