Explanation:
revising is studying a material you do not quite understand and wish to know further. It is used before tests to study curicillum.
The answer is the word "studying."
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.
The correct answer is B) World Trade Center and Osama Bin Ladin. Hope this helps.
The two forces that struggle in a conflict are right and wrong. If there's a problem there is always a solution. There is a wrong way to fix it and a right way, they are both struggling to win. Like a villain and a hero or the protagonist and the antagonist.