30 1.desert plants: plants that live in a desert biome have developed ingenious ways to save precious moisture. many cacti have thick stems filled with pulpy material in which they store lots of water. acacia trees shed their leaves to avoid losing moisture by evaporation. the joshua tree’s needle-like leaves with a waxy coating cut down on exposure to sunlight while they reduce evaporation. a. what is the main idea of the above paragraph? b. what are three details that support the main idea?