| 1 | Flight 737 will board passengers. | |
| 2 | So is the Oasis of the Seas, which is the largest passenger ship in the world. | |
| 3 | What happens, some critics ask, if tragedy befalls a passenger flight? | |
| 4 | Others argue that more bus routes should be opened up because buses can accommodate more passengers. | |
| 5 | But in the long term, cars contributed more to warming than planes did on a kilometer-per-passenger basis. |