Chlorpheniramine is an antihistamine that reduces the effects of natural chemical histamine in the body. Histamine can produce symptoms of sneezing, itching, watery eyes, and runny nose. Chlorpheniramine is used to treat runny nose, sneezing, itching, and watery eyes caused by allergies, the common cold, or the flu.
The mean orbital velocity of Earth is about 29.783 kilometers per second. That's the speed the planet is moving through space in its orbit about the sun. Earth's speed varies a bit because its orbit is slightly eccentric, but that's why we say mean orbital velocity. One can calculate this value by knowing two facts:
   Any object with mass has an escape velocity. The escape velocity is  the velocity at which an object must travel in order to escape the  gravitational pull of the massive object. The escape velocity of  the Earth is 11.186 kilometers per second (a little over 25,000  miles per hour).