How can you tell the difference between alternate and opposite leaf arrangements

 You can tell the difference between alternate and opposite leaf arrangements based on whether the leaf has one or two leaves at the node. Alternate leaf arrangement is when a single leaf is attached at one location on the stem, the node, in an alternating pattern.  On the other hand, the opposite leaf arrangement is when two leaves are attached to the same node on opposite sides of the stem.  

i am going to guess that it is co2.