Adenine and guanine have a fused-ring skeletal structure derived of purine, hence they are called purine bases. ... Similarly, the simple-ring structure of cytosine, uracil, and thymine is derived of pyrimidine, so those three bases are called the pyrimidine bases.
The answer is B. The specific heat means the heat amount the substance needs to absorb when the temperature increases 1℃. The high specific heat means that it needs a huge amount of heat when increase just 1℃. For A, the dissolved salts can help decrease the freezing point.
The adult heart pumps about five quarts of blood each minute so around 2,000 gallons<span> of blood each day.A typical athlete's heart churns out up to </span>eight gallons<span> of blood per minute.</span>
