单项选择题
A.八达岭 B.龙庆峡 C.白龙潭 D.故宫
A.Pleasebecautious B.Pleasekeepyourhandinsidethebus C.Pleaseholdfastandsitsecurely D.Pleaseexitfromthebackdoor
A.Seeyou B.Goodmorning C.Welcome D.Youtoo