［参考范文］ Ladies and gentlemen: Here we are at the foot of the Great Wall. It’s the longest wall in the world and has a history of over 2000 years. It’s one of the wonders of the world. we will spend two hours on the wall. It’s 8:30 now. We’ll leave at 10:30. The bus will be waiting for us at the entrance. Please remember our bus number and be back on time. Besides, please take your valuable things with you and shut all the windows before getting off. Have a good time! Thank you.