Figure 2 demonstrates the process which transports gasoline from an oil depot to a gasoline station. In Figure 2, there are three transportation ways. The Figure 2(A) shows the first transportation way, which includes the following steps:
Take out gasoline barrels from the oil depot.
Pour gasoline into the oil tank truck.
The oil tank truck goes to the square before the gas
station.
Pour gasoline from the oil tank truck into gasoline
barrels.
Pour gasoline into the gas station.
Figure 2(B) shows the second transportation way, which includes the following steps:
Take out gasoline barrels from the oil depot.
Put gasoline barrels on the road.
Gasoline barrels roll onto the square before the gas
station.
Take back gasoline barrels from the road.
Pour gasoline into the gas station.