On a straight-line demand curve using the geometric method: elasticity equals 0 at the X-axis intercept (E), is less than 1 between the mid-point and the X-axis intercept (C), equals 1 at the mid-point (A), is greater than 1 between the mid-point and the Y-axis intercept (D), and is infinite at the Y-axis intercept (B). Increasing order: E, C, A, D, B.