Several days after a snow fall some houses still have roofs covered with snow while other roofs are clear because the snow melted relating to this home insulation why does this happen

answer; i believe that the correct answer is(d) nondisjunction during meiosis;

geologic time scale (for gradpoint) =)

blood enters the heart through two large veins, the inferior and superior vena cava, emptying oxygen-poor blood from the body into the right atrium of the heart. as the ventricle contracts, blood leaves the heart through the pulmonic valve, into the pulmonary artery and to the lungs where it is oxygenated.