三、鍋爐之分類方法有三種，即依用途、燃氣及水所在之位置、爐水循環狀況等三種情況分類。請分別詳細說明各鍋爐分類之內容。（20 分）

四、請將下列英文譯成中文。（20 分） The rate of flow of heat through a heat exchanger tube or plate from the fluid at the higher temperature to the one at the lower is related to the temperature difference between the two fluids, the ability of the material of the tube or plate to conduct and the area and thickness of the material.