cars=['ford','bmw','lamborghini']
cars.sort()
print(cars)
cars.sort(reverse=True)
print(cars)
cars=['ford','bmw','lamborghini']
print(sorted(cars))
print(cars)
cars.reverse()
print(cars)
c=len(cars)
print("a single ",c,"two single ",c)

places=['xian','beijing','xiaman','qinghai','luguhu']
print(places)
print(sorted(places))
print(places)
print(sorted(places,reverse=True))
places.reverse()
print(places)
places.reverse()
print(places)
places.sort()
print(places)
places.sort(reverse=True)
print(places)
print("there are",len(places),".")


