What is the passage mainly about?

How tree rings record past years and can be joined into a long dated record. (The passage moves from one tree's rings, to the shared regional pattern, to chained overlaps that reach back thousands of years.)

According to the passage, what does a narrow ring show?

That the year was dry. (The text pairs a wet, mild year with a wide ring and a drought with a narrow one.)

What must be true before a wooden beam can be given an exact calendar date?

Its ring pattern must overlap with a pattern that is already dated. (Dating works by matching the beam's rings to an existing sequence; without an overlap, the beam cannot be tied to calendar years.)

In this passage, 'beam' means:

a long piece of timber used to build with (The beam is 'cut from an old farmhouse' and 'carries rings', so it is a piece of building timber.)

The Diary Inside A Tree: Level 3 Reading Comprehension Questions

Cut across the trunk of an old oak and you meet a set of rings. In climates with a real winter, the tree adds one ring a year: pale, quick wood in spring, dark, tight wood late in the season. Count the rings and you have the age of the tree. Measure their width and you have something better, a record of the years themselves.

A wet, mild year leaves a wide ring. A drought leaves a narrow one. Because every tree in a region meets the same weather, the trees of that region share one pattern of wide and narrow bands, like a barcode.

That shared pattern lets researchers reach back further than any living tree. A beam cut from an old farmhouse carries rings too, and if the outer rings of the beam match the inner rings of a living trunk, the two records can be joined. Chain enough overlaps together and the sequence runs back thousands of years, with every ring tied to an exact calendar year.

Archaeologists use those sequences to date buildings and ships. Climate scientists use them to test what the weather did long before anyone wrote it down.

Comprehension questions