35. Lions can live in Africa because they can _______ water for up to one month. They have no trouble during dry times. (A) go through (B) go without (C) go on (D) go forward

40. Scientists say feral pigeons are a valuable way of probing contaminants in environment, ___ they are exposed to the same air, water, food and other factors as humans, and don’t venture far from home. (A) although (B) hence (C) because of (D) since