Africanized honey bees were created in brazil in 1957. is this the author's thesis?

Absolutely NOT. A thesis is NEVER a statement of fact. It is instead the writer's opinion.

Answerrespectpresentation;

Betray, destroy, and obey do not need to be changed to add the suffix -ed, because the "y" at the end of each word is preceded by a vowel  (so  they would be spelled  "betrayed," "destroyed," and "obeyed").

but hurry is different; it has to  be spelled "hurried" because the "y" at the end of "hurry" is preceded by a consonant.