老师说；“Good afternoon ， class！”学生应该说__________________.

根据短文内容，选择正确答案。  

    Here is a photo. The two girls have big blue eyes and long brown hair. They are both ten years old. They are in the same class. The one in a yellow skirt is Lily. The other one (另一个) an orange skirt is Lucy. Their father (父亲) is Mr. White. He is in a brown coat. Their mom is Mrs. White. She is in a black dress. Who is that boy in a blue cap? He is Lucy and Lily's brother(哥哥), Bob. He is a high school student. Look! Lucy and Lily are in a green car.

   Steven Jobs, the designer of Apple Computer, was not clever when he was in school. At that time, he was not a good student and he always made troubles with his schoolmates. When he went into college, he didn't change a lot. Then he dropped out（退学）. But he was full of new ideas.
   After he left college, Steven Jobs worked as a video game designer. He worked there for only several months and then he went to India. He hoped that the trip would give him some new ideas and give him a change in life. Steven Jobs lived on a farm in California for a year after he returned from India.
   In 1975, he began to make a new type of computer. He designed the Apple Computer with his friend in his garage (汽车库). He chose the name "Apple" just because it could help him to remember a happy summer he once spent in an apple tree garden. His Apple Computer was such a great success that Steven Jobs soon became famous all over the world.

在“小白兔与狼外婆”的故事中小白兔能分辨出门外不是自己的外婆，主要是依据声音的（     ）