The wave (A) lengths of ultraviolet light are (B) short than those are (C) visible light but longer than those of X-rays
(A) All thoroughbreds are descended (B) from three Arabian (C) stallion imported (D) into England between 1689 and 1724.
By (A) measuring the rate of decay of potassium isotopes in volcanic ash, scientists (B)can date the layers of volcanic ash and any human (C)remains in (D) they.
(A) Hundreds of partial (B)to complete fossil skeletons of triceratops have been (C) gather in North America from (D)rocks of the late Cretaceous period.
By (A) the time of the dinosaurs, turtles (B) have already developed the hard shell (C)into which their heads and legs could be (D)drawn.