- Grade 11 and 12 Mathematics (Moderator: geoffrey)
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- Grade 11 and 12 Mathematics (Moderator: geoffrey)
As the western states of America were settled, pioneers often had to drink rancid water from ponds and other sources. This often resulted in chronic diarrhea, causing many cases of dehydration and death that could have been avoided if clean water had been available.
When blood is exposed to air, it clots. Heparin allows the blood to come in direct contact with air without clotting.
The horizontal fraction bar was introduced by the Arabs.
The average older adult in the United States takes five prescription drugs per day. Half of these drugs contain a sedative. Alcohol should therefore be avoided by most senior citizens because of the dangerous interactions between alcohol and sedatives.
Astigmatism is the most common vision problem. It may accompany nearsightedness or farsightedness. It is usually caused by an irregularly shaped cornea, but sometimes it is the result of an irregularly shaped lens. Either type can be corrected by eyeglasses, contact lenses, or refractive surgery.