题目

   Elephants are famous for their supposedly excellent memory. Now it seems that they are good at simple math too.    Researchers at the University of Tokyo have found an Asian elephant named Ashya can add small quantities together and correctly identify(识别）which is larger.    For example ,when researcher Naoko dropped three apples into one bucket and one apple into a second, then four more apples into the first and five into the second, Ashya correctly identified that the first bucket contained more apples and began munching(嚼）on her tasty prize. Ashya chose the correct bucket我国山区面积广大，这里最容易发生的地质灾害是（　　）A．台风B．泥石流C．洪涝D．干旱