【正文】
m in winter. Indeed, wood _______ (be) important in our everyday life.Where ________ wood __________ (e) from? It ________________ (take) from trees which _____________(grow) in the mountains. _________ you ____________ (know) how it ____________ (get) to us from the mountains?First of all, trees ___________(cut) down when they ______________(grow) big enough. Then their branches _______________ (cut) off, and logs _______________(make).These heavy logs ________________(put) together in different ways and _________________ (take) down to the foot of the mountains. Some of them _________________ (float使漂流) down the small rivers and others _________________ (carry) down on trains.Big trees ________________(cut) down in the mountains every year. Then young ones ___________ (must, plant) so that we ______ always ____ (can, have) enough wood. We have to take good care of mountains so that they __________always __________(may, cover) with growing trees.課后提升1. Review the passive voice.2. Finish the exercises.4用心 愛心 專心