What is other word for carefully looking at an object or process beginning with the letter o and is 8 letters long

The table shows dates and appearance of index fossils. which rock layers can be dated most precisely? a) a layer containing both a fossil 4 and a fossil 3 b) a layer containing both a fossil 2 and a fossil 3 c) a layer containing both a fossil 1 and a fossil 4 d) a layer containing both a fossil 1 and a fossil 2

Which of the following is not a possible effectof increasimg carbon dioxide levels in the atmosphere ?

Which of these is not a nucleotide base found in dna?