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Fungal nail infections account for up to 30% of all skin infections. They affect 5% of the general population—mostly people over the age of 70.
After a vasectomy, it takes about 12 ejaculations to clear out sperm that were already beyond the blocked area.
Side effects from substance abuse include nausea, dehydration, reduced productivitiy, and dependence. Though these effects usually worsen over time, the constant need for the substance often overcomes rational thinking.
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.
Sperm cells are so tiny that 400 to 500 million (400,000,000–500,000,000) of them fit onto 1 tsp.
![Cradle the head briefly in both hands to end this section. Hold for a few seconds until you can feel ...](https://biology-forums.com/gallery/33/medium_380798_23_08_17_1_47_42_33124348.jpeg)
![Hold baby’s hands and (A) cross arms over chest and then (B) open out to the sides. Repeat several ...](https://biology-forums.com/gallery/33/medium_380798_23_08_17_7_43_56_33345868.jpeg)