When studying tree rings, why is simply counting the rings not an effective method of study

Identify the statements that correctly identify a fact about georgia's five regions.

Read the paragraph and answer the question that follows: the town of belmond, iowa, needs to add weather sirens. the loud and steady wail would warn citizens of approaching danger. if past history is an indication, the sirens will save hundreds of lives. with a prediction of a deadly storm season, the alert which sentence should be revised to eliminate redundancy? the town of belmond, iowa, needs to add weather sirens. the loud and steady wail would warn citizens of approaching danger. if past history is an indication, the sirens will save hundreds of lives. with a prediction of a deadly storm season, the alert system is needed immediately.

It has been reported that the dna of the elephant shark has barely changed over the last 420 million years. which statement explains why the elephant shark has not changed over time?