12.4

1. 1. Listen to Track 109.

      Now answer the questions.

   1. What is the lecture mainly about?

      1. The use of a defense mechanism by various animals
      2. Predators that threaten the African crested porcupine
      3. One way that animals avoid detection by predators
      4. The application of animal toxins in medicine

   2. According to the lecture, what are three weapons used by animals to protect themselves from attack? Choose 3 answers.

      1. Quick evasion
      2. Toxins
      3. A poisonous sea anemone
      4. Avoidance of detection
      5. Spines

   3. According to the lecture, when do African crested porcupines attack?

      1. Only when faced with predators larger than themselves
      2. Only once they are fully grown
      3. When their attempts to scare a predator away fail
      4. Whenever they are startled by a potential predator

2. 1. Listen to Track 110.

      Now answer the question.

   4. 1. To admit a flaw in her own logic
      2. To express momentary confusion
      3. To ask students to describe how animal weapons look
      4. To introduce the next topic

   6. 1. Listen to Track 111.

         Now answer the question.

      5. 1. To question whether a fascinating theory should be trusted
         2. To emphasize the importance of further study in this area
         3. To explain how certain animals use fangs effectively
         4. To present an unexpected type of defense mechanism

   7. 1. Listen to Track 112.

         Now answer the question.

      6. 1. The porcupine is typically successful at scaring off predators.
         2. The porcupine prefers to escape detection or run away from predators.
         3. The porcupine is likely to attempt to scare a potential predator away before attacking.
         4. The porcupine has few natural predators.