Oxygen was absent on earth
If a deep-ocean trench is located adjacent to a continent, active volcanoes would likely be found landward from the trench.
Answer:
Carbohydrates contain only carbon, hydrogen and oxygen atoms; prior to any oxidation or reduction, most have the empirical formula Cm(H2O)n. Compounds obtained from carbohydrates by substitution, etc., are known as carbohydrate derivatives and may contain other elements.
Explanation:
Answer:
Polar air masses derived from areas close to Iceland and tropical masses from the Azores bring, respectively, very different conditions of temperature
Explanation:
