Eggs that you buy from the store will not stay fresh for long  without refrigeration. Eggs that come right from the chicken can  kept at room temperature for weeks. Store bo â¦ ught eggs should be  refrigerated within a few hours of buying them just to be safe.ven with its natural (but easily cracked) calcium-carbonate container, a hard-cooked egg is a perishabl â¦ e food, so it shouldn't be kept at room temperature for more than two hours.   If kept in an unbroken shell and in the refrigerator about a week.
The human range is commonly given as 20 to 20,000 Hz, though there is considerable variation between individuals, especially at high frequencies, and a gradual loss of sensitivity to higher frequencies with age is considered normal. Sensitivity also varies with frequency, as shown by equal-loudness contours.
The length of a human pregnancy can vary naturally by as much as five weeks, according to new research. Share: FULL STORY. The length of a human pregnancy can vary naturally by as much as five weeks. Credit: Â© Jessmine / Fotolia. The length of a human pregnancy can vary naturally by as much as five weeks, according to research published online August 7 in the journal Human Reproduction. Normally, women are given a date for the likely delivery of their baby that is calculated as 280 days after the onset of their last menstrual period.