It doesn't. Dophins - just as whales - come to the surface to breathe air. Then they can stay underwater for 8 to 10 minutes before they have to come up for air again. For breathing they have a blowhole on the top of their skull.
They give birth to a single calf after a gestation period of 12 months, twins are rare.
No. However, it is possible to run the Windows version of DOSBox under MS-DOS and compatibles using HX DOS Extender. HX DOS Extender allows you to run a limited number of Windows applications under DOS. DOSBox, QEMU, Bochs, and a couple other emulators can be run using this method.
It can't be run in DOS mode because it relies on Windows-specific APIs. DOS mode is running the program in either DOS, or in a DOS box under Windows. Basically, it is saying that it can't run on DOS because it is not a DOS program.
a river.
It learns how to
slowly
Not only in DOS but in any OS user communicate with OS by shell.
Shell..
command prompt
Synchronize
Synchronize
command prompt