Please choose the correct ending to complete the given sentence: Cars & Other Vehicles: [header] How to transport a motorcycle [title] Park the truck and motorcycle on a firm, level surface. [step] Never attempt to load a motorcycle into a pickup truck on uneven ground, or soft ground that may give way as you move the motorcycle. Black top or concrete are the preferred surfaces to use when loading your bike into a pickup truck.

Ending1: [substeps] If you're uncertain if a truck is a good choice for loading your motorcycle, try washing your bike before loading it. This will reduce the chance of mud or germs entering the truck's cargo area. Ending2: Unless they are fairly breathable, strollers may be used as long as they are not touching the ground. [substeps] Ideally you should lift the motorcycle out and close the front door to the truck. Ending3: [substeps] Never use pieces of wood on grass or dirt as a loading surface, as the wood may sink, break or slide. Do not attempt to load a motorcycle into a truck on an uneven surface to prevent falling over or dropping the motorcycle itself as you load it. Ending4: [substeps] If you are headed for a particular carwash or crevice, make sure the terrain is flat. If it is damp or icy the bike will easily fall under the load, and you will likely have to remove the bike in the pickup truck.

Answer format: ending1/ending2/ending3/ending4