实战演练：I. 1. exist 2. allow 3. invent 4. offered
5. preparing/ prepared
听力专项训练：I. 1. standing 2. long necks
3. careful 4. half an hour
I. How do giraffes sleep? They can sleep both lying on the ground and standing. Although their long necks make it hard for them to get up again, giraffes like to sleep lying down. Wild giraffes have to be careful because of their enemies. They usually sleep for just half an hour a day.
II. Dear John,
I got your letter from my teacher. It's nice to hear from you!
My name is Jack. I am 12. I live in Beijing. I am a student at Jinghua Middle School. I’m in Class 3. My teacher is Miss Lee. She is not only our English teacher, but also our class teacher.
I have two good friends at school. They are Susan and Sally. They are twins. They come from Britain. They like China very much. They teach me English and I teach them Chinese.
I hope to hear from you soon! Take care.