Why is the blood that flows from the lungs toward the heart a brighter red then the blood that flows the other direction

Which number represents a basic ph, 4 or 9? numerical answers expected! answer for blank 1: i'll give

Abird flies by moving its wings up and down. which two systems are most directly responsible for the movement of a bird's wings? a. skeletal and muscular systems b. respiratory and muscular systems c. skeletal and digestive systems d. respiratory and digestive systems

When a chemical spill has occurred on your clothes you should 1. scream for 2. run under the shower and turn it on 3. use the eye wash station 4. grab the first aid kit