the trend skull material with different angel

l, or cranium, is a bony structure of Craniates which serves as the general framework for a head. The skull supports the structures of the face and protects the brain against injury. See more at Wikipedia.org...

[rend has a number of possible meanings:In statistics, a trend is a long-term movement in time series data after other components have been accounted for. In statistics, a trend may be described in hypothesis testing, where a test has failed to achieve the benchmark for statistical significance, i.e a P-value of less than 0.05) but no more than 0.01. This usage is relatively common in research studies of psychology, and often indicates the need for replications and future studies using a larger sample size. In technical analysis of financial markets, trend is the existing general direction of energy expressed as the relationship between prices. It is the discovery and monitoring of human nature that leads to the actions of speculators and investors. See more at Wikipedia.org...]