Please choose the correct ending to complete the given sentence: Education and Communications: [header] How to identify an ash tree [title] Pull down a branch from the tree so that you can view it more easily. [step] You can also pick up a dead stick that has already fallen to the ground. [title] View whether the branches have opposite branching.

Ending1: [step] If the branches are clearly together, the ash tree is fir. If they are individually branching, the ash tree may be spruce. Ending2: [step] From underneath, you will see a column of branches dividing the ash tree into thirds. This is called a " branching branch ", and it is located both to the left or right of the tree. Ending3: [step] This means that branches originate from the same point when they extend from the main branch. Other trees have alternate branching, with branches alternating left and right as they grow from the main branch. Ending4: [step] Some ash trees have absolutely opposite branching branches on all sides, including two main branches: a helix branch and an akhra branch. [title] Inspect the branches from different angles to see if they match up.

Answer format: ending1/ending2/ending3/ending4