Concurrent
intermittent
normal
Another word that means the same is "synonym." A synonym is a word that has the same or nearly the same meaning as another word. For example, "happy" and "joyful" are synonyms.
The word 'unite' means close to the same thing as annex does.
promote
The word that means happening before the usual time is "premature." It is often used to describe events, actions, or developments that occur earlier than expected or appropriate.
Simultaneously.
coincidence
Simultaneously.
"Ibid." is an abbreviation of the Latin word which means just that.
Inevitable
prevent
intermittent
Prevention means to keep something from happening.
The word simultaneous is an adjective. It describes two or more things happening at the same time.
The word is exodus.
likely