Please choose the correct ending to complete the given sentence: Education and Communications: [header] How to study reactive intermediates [title] Note that an organic reaction occurs in one of two ways. [substeps] The first way is through a concerted reaction that takes place in a single step, with only one transition state. The second way is through a non-concerted reaction, which results in intermediate structures consisting of highly reaction carbon species.

Ending1: Plant interspecies formation comes first. Because of this, it is not necessary to observe a process using an intact layer of gut matter. Ending2: Interjecting into a humans futures study helps to detect and organize these leads. The two fundamental commonalities strengthen a human development process through the development of an ethical overarching influence. Ending3: Expandable carbon has been increased by 29 %. The only time an active reaction happens in an active science occurs is through other actions. Ending4: This is the dominant sort of chemical reaction. [title] Observe organic reactions using a special spectroscopic technique.

Answer format: ending1/ending2/ending3/ending4