The first one because just think about how light oxygen or air is
Through analysis of ice cores, scientists learn about glacial-interglacial cycles, changing atmospheric carbon dioxide levels, and climate stability over the last 10,000 years. Many ice cores have been drilled in Antarctica.
Answer:
On January 22, 2001, EPA adopted a new standard for arsenic in drinking water of 0.01 mg/l or 10 parts per billion (ppb), replacing the old standard of 50 ppb. Water systems had to meet the new standard by January 23, 2006.
Explanation:
Canada, one of the wealthiest countries in the world, is also one of the most water-rich. The province of Ontario shares the Great Lakes—which contain 18 percent of the world’s fresh surface water—with the United States. Access to sufficient, affordable, and safe drinking water and adequate sanitation is easy for most Canadians. But this is not true for many First Nations indigenous persons. In stark contrast, the water supplied to many First Nations communities on lands known as reserves is contaminated, hard to access, or at risk due to faulty treatment systems. The government regulates water quality for off-reserve communities, but has no binding regulations for water on First Nations reserves.
Answer:
The answer is day 14 - / + 3 days
Explanation:
In a 28-day menstrual cycle the most likely days for a woman to become pregnant is from day 14 - / + 3 days, that is, days 11, 12, 13, 14, 15 and 16. She should be educated, If she is in search of pregnancy, take the vaginal temperature and realize how the viscosity of the abundant flow begins to present.