... (B) are (C) difference types of (D) dunes 2) (A) Sahara (B) is named (C) after Simpson (D) in 192 9 3) Space (A) seem to have (B) no limit (C) in the (D) desert 4) (A) Rabbit are one of the agents ... plants provide essential foods and can also be used in medicines If species 7) _ extinct, their potential value will never be known The scale of destruction is enormous Swamps, forests, grasslands ... been destroyed Coral reefs, called the forests of the ocean because they are so rich in life, are 9) _ around the world We must limit the damage to habitats now 10) _ they remain a valuable...