For women, there are things called "Sperms". There is an <em>egg </em>in the women. Think of colors. Say an orange sperm is a boy and a yellow sperm is a girl. If the yellow sperm reaches the egg first, the baby will be a girl. If the orange sperm reaches the egg first, the baby will be a boy. Think of it as a Sperm-race.
If two yellows, two oranges, or one of each comes to the sperm at the same time, you'll have twins.
Same with triples, quadruplets, etc, even though this is very rare.
Can I have Brainliest?
A common way for infectious diseases to spread is through the direct transfer of bacteria, viruses or other germs from one person to another.
Answer:
Carbon dioxide
Explanation:
Because The heart pumps the oxygen to the muscles that are doing the exercise. When you exercise and your muscles work harder, your body uses more oxygen and produces more carbon dioxide.
