Direction: Sequence the sentences and enter as a digit string (e.g. "53412").
1. Once they reach a high altitude, they manage to travel all over the world.
2. An expert from the team explained that the bacteria usually lived on the surface of vegetation, such as leaves.
3. The wind carries them off the surface and into the atmosphere.
4. A group of researchers were surprised to find that clouds had carried drug resistant bacteria over a long distance.