Completar frases Wood 1Versión en línea Wood as a technical material (I) por Fernando Martínez 1 natural softwoods Softwoods Heartwood sapwood centre builders heartwood Hardwoods heavy harder material strength hardens manufacturing annual bark hardwoods evergreen ring deciduous Wood is a that has been used for many centuries by and craftspeople . There are two basic types of wood : hardwood and softwood . are generally than and come from trees . come from trees . They are not usually as as . Each year a new layer of growth is added just below the , producing an . New growth is called . New layers grow on the outside and the centre to form . is found at the of a tree and is the best part of a tree to use for , because of its hardness and .
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