Sugar is a monomer called monosaccharides and sugar cubes are polymer because a polymer has a molecular structure
Chloroplast is the organelle that performs photosynthesis
Answer:D
Explanation: The pulmonary air sacs of birds only permit a unidirectional flow of air through the lungs. Unidirectional flow means that air is inhale and exhale through one trachea alternatively. This means the bird lungs only receive largely fresh air which has a high oxygen content during inhalation and do not receive fresh during exhalation. While air flow bidirectional in mammals.
X= -2
5x + 15 + 2x = 4x + 9
7x + 15 = 4x + 9 (subtract 4 from each side)
3x + 15 = 9 (subtract 15 from each side)
3x = -6 (divide by 3 on each side)
X= -2
