五、試述苗木猝倒病（damping off）的病徵、傳染路徑及防治方法。（20 分）

⑴ New Orleans is and always has been a doomed city. Levees and loss of wetlands did not cause it to sink—they simply sped up the process. No city can exist 20 feet below sea level. If the Federal Government seeks to rebuild the city, instead of relocating the people, it is committing future generations to a similar fate.