Answer:
Hydrogen bonds make water molecules spread out when they freeze. This makes ice less dense than water and allows ice to float. If ice did not float then oceans and lakes would freeze from the bottom up, killing marine life by trapping organisms in the ice. When ice floats, it insulates the water below, keeping it at around 4 degrees C or 40F, which does not freeze and allows fish to survive the winter.
Explanation:
DRIs is the general term for a set of reference values or guidelines that are used to plan and asses nutrient intakes of healthy people. These values which vary by age and gender include:
- Recommended Dietary allowance (RDA): average daily level of intake sufficient to meet nutrient requirements of about 97 - 98% of healthy people.
-Adequate intake (AI): established when evidence is not sufficient to develop an RDA and is set at a level assumed to ensure nutritional adequacy.
- Tolerable Upper Intake (UL): Maximum daily intake unlikely to cause adverse health effects.
DRIs are not necessarily found on labels because there is no law requiring that they must be placed there.