【单选题】听力原文: Windbreaks are barriers formed by trees and other plants. Farmers plant these barriers around their fields to protect their land. Windbreaks stop the wind from blowing soil away (33) . They also...
【简答题】Plants are very important. This is because plants can make food from air, water and sunlight. Animals and man cannot make food from air, water and sunlight. Animals can get their food by eating plants...