.Unit5Topic1重点短语1. a great number of rivers2. fetch sb. sth.=fetch sth. for sb.3. introduce sth. in detail4. lie in/ lie on/ lie to5. go through.6. be well worth doing sth.7. above sea level8. experience four seasons in a day9. hear of/ hear from 10.be surrounded by 11.lose oneself in 12.serve as a bridge 13.connect sth. with sth. 14.be known as15.have a chance to do sth. 16.be considered as/ 17.various/ all kinds of 18.protect against 19.be covered with重点句型
