reduces the oxygen content and increases the carbon monoxide of the mother's blood. This quickly reduces the oxygen available for the fetus. Further, the respiration rate slows and speeds up its heart. Nicotine and toxins appear in the blood.

Smoking nicotine based product such as cigarette

Explanation:

When a pregnant mother smoke, she intakes various harmful chemicals such as lead, arsenic, nicotine, carbon monoxide etc. These harmful toxic substances directly mix with the blood and are carried to the fetus in the womb of the mother. The oxygen content in the blood reduces due to which the heart beat rate of the baby increases and there are high chances of baby developing some kind of respiratory disorder.

paper covers rock.

explanation:

rock only smashes scissors.