An example of MS-DOS's command-line interface, this one showing that the current directory is the root of drive C. MS-DOS (/ËÉmÉsËdÉs/ EM-es-DOSS; acronym for Microsoft Disk Operating System) is a discontinued operating system for x86-based personal computers mostly developed by Microsoft.
Written by: Kierstan Boyd. Nov. 08, 2012. The main symptom of vitamin A deficiency is vision loss and blindness. Vision loss often begins as a problem adjusting to seeing in the dark, or night blindness. People with night blindness do not see well in the dark, but are able to see normally if enough light is present.
Symptoms of Vitamin B12 Deficiency. If you have vitamin B12 deficiency, you could become anemic. A mild deficiency may cause no symptoms. But if untreated, it may lead to symptoms such as: Weakness, tiredness, or lightheadedness; Heart palpitations and shortness of breath; Pale skin; A smooth tongue; Constipation, diarrhea, loss of appetite, or gas