Unit 51. keep our balance 保持平衡 2. fall down 摔倒 3. have a cold 感冒 4. the sense of sight / hearing / smell / taste / touch视觉/听觉/嗅觉/味觉/触觉 5. as soon as 一就 6. walk into 走进 7. go to the reception desk 走向接待台 8. book a room 预定一间房 9. welcome sb. to do sth. 欢迎某人做某事 10. be blind in （哪只眼）瞎 11. sound like 听起来象 12. seem like 看起来象 13. at once立刻14. lead sb. to the room personally 亲自领着某人到房间 15. Can you tell me the location of the fire exit？ 你能告诉我防火的安全出口在哪里吗？
