37. When communities thrive, they__________ . (A) lay waste (B) are eliminated (C) work side by side (D) develop very successfully

43. Which of the following is NOT true according to the passage? (A) The shape of a blimp is supported by a metal frame. (B) Only the ground crew is needed to make a blimp fly. (C) A blimp needs a small engine to decide its direction. (D) Helium makes it possible for a blimp to rise.