Please choose the correct ending to complete the given sentence: Travel: [header] How to pack a backpack [title] Choose your backpack. [step] With dozens of backpacks on the market these days, it may be difficult to select the best one for your life and travel commitments. Backpack sizes are measured in the number of liters they can carry, and range from 20-80 + liters each.

Ending1: Most backpacks are relatively gentle on the skin and cannot be physically susceptible to damage due to heavy wear. Take the following into consideration as you decide what to include in your backpack : [substeps] Large lightweight bags: these bags are dense and compact, so they can fit on your shoulder. Ending2: [substeps] Heavier backpacks let you carry more weight around your midsection. Bulky backpacks, like the kind used by transport drivers, can add weight to your pack without exactly fitting. Ending3: To get the most practical and secure backpack you want, look over at various construction websites and research a backpack that's one hundred percent durable. [substeps] The address of the school where the school is located when traveling to broaden your choices. Ending4: Consider the length of your trip (s), your torso size, and the conditions under which you are backpacking. Whenever possible, choose a smaller and therefore lighter pack to make traveling more comfortable.

Answer format: ending1/ending2/ending3/ending4