An advantage of using longitudinal studies is that A. they are relatively inexpensive
B. they take little time to conduct
C. they generally have small amounts of data
D. subject variation is often reduced

Name the bone/structure/process that fits the following description: a) a bone with a complex shape. b) found in the medullary cavity. c) a large, rough process. d) it is thin, like a plate. e) shaft of a long bone. f) a mature bone cell. g) a large, round, smooth process. h) it covers outer surface of bone. i) a shallow depression on surface of bone. j) a roughly cube-shaped bone. k) the covering of epiphysis. l) a very narrow ridge of bone. m) space between lamellae for an osteocyte. n) chamber within diaphysis o) also called wormian bone. p) it secretes new matrix. q) end of a long bone. r) a small, round hole. s) a matrix, arrangement in spongy bone. t) it is a chamber within a bone. u) a network allowing osteocytes to receive nutrients. v) one example is the patella. w) it houses artery, vein and nerve. x) almost flat, smooth surface of a bone. y) a narrow, pointed process.