DCDR and VCDR
Dec. is the correct abbreviation
Ave.
Both are correct. "Do" is an auxiliary verb.
correct
Have done is correct. When using have as an auxiliary verb, it's paired with a past participle.
The correct spelling is auxiliary (assisting or supporting, or an assisting device or group).
Your spelling is correct
Because when you use an auxiliary, the verbs are always normal. Because the auxiliary is passing the sentence to the correct tense form.
There are no "correct" abbreviations for birds. The first syllable usually works: car.
An auxiliary verb.
"Will be sent" is correct. It follows the correct passive voice construction with the past participle "sent" after the auxiliary verb "will be".
That is the correct spelling of the noun "division" (dividing).