This can show up anywhere from a few weeks of age and up to the fourth month of life. (newkidscenter.com)
He instilled a love of music in Ruby from a very young age — she had her own playlist at a few weeks of age and seems to have an affection for Elvis Costello. (openadopt.org)
By a few weeks of age, before falling sick, these animals had about half the normal number of so - called memory T cells. (sciencemag.org)