Reading: Fill in the Blanks — practice #rfib-002

Each year a tree adds a new ring of wood, and the drop here of these rings reveals a great deal about the past. Wide rings form in warm, wet seasons, while narrow ones drop here that the year was cold or dry. By measuring the rings carefully, scientists can drop here the exact age of a piece of timber and even reconstruct the climate of distant centuries. The method has become an invaluable drop here for archaeologists dating ancient wooden structures.