Answer:
hello
Explanation:
It surely was a historical Event.
The use of "a" instead of "an" before "historical" is based on the pronunciation of the word "historical." The general rule in English is to use "an" before words that start with a vowel sound and "a" before words that start with a consonant sound.
And "historical" starts with the letter "h," the "h" is pronounced in most dialects of English, making it a consonant sound.