Facebook eventually filed for an initial public offering on February 1, 2012. Facebook held an initial public offering on May 17, 2012, negotiating a share price of US$38. The company was valued at $104 billion, the largest valuation to date for a newly listed public company.
No one knows what causes these small, painful blisters inside your mouth. Triggers include hypersensitivity, infection, hormones, stress, and not getting enough of some vitamins. Also called aphthous ulcers, canker sores can show up on the tongue, cheek, even your gums.
Common causes of mouth ulcers. The most common causes of mouth ulcers are related to disturbances of the mouth and include: 1  Bacterial infections. 2  Canker sores. 3  Dietary deficiencies, such as lack of vitamin B-12, zinc, folate (folic acid), or iron. 4  Emotional stress. 5  Food allergies. 6  Nutritional deficiency. 7  Spicy foods.