This is false because saliva is the has one of the most bacteria within the human body. If it is not cleansed cavities will grow and effect your teeth, gums and more.
While brushing your teeth at least twice a day is essential to good oral hygiene, brushing alone only removes up to 70% of bad bacteria and can't protect your teeth from the buildup of plaque or the breakdown of tooth enamel. But just because of that doesn't mean that cleaning your teeth twice a day isn't a good habit.
The American Dental Association recommends brushing your teeth twice a day with fluoride toothpaste for two minutes each time. When you brush your teeth, you help remove food and plaque — a sticky white film that forms on your teeth and contains bacteria.
Eating a nutritious diet during pregnancy is linked to good fetal brain development, a healthy birth weight, and it reduces the risk of many birth defects.
Abstinence means to avoid or not want to do something. It is preferred that high school children under the age of 18 restrain from sexual activity. (Hope this helps if it did pls mark brainliest!)