Object: Backpack
the 1st backpack is called daypack, it is orange and the both strap lengths are 20cm.
changed the LEFT strap length to 25cm.
daypack is open.
let's start packing!
daypack contains: a laptop, a waterbotle, and a lunch box.
daypack is full.
daypack contains: a laptop, a waterbotle, a lunch box, and a charger.
======================================
the 2nd backpack is called travelpack and it is 40L.
travelpack is closed.
The 1st item in travelpack is a toothbrush.