Temporary methods of birth control are not hundred per cent perfect. Why?

Explanation

**Step-by-Step Solution:**

1. **Definition of Temporary Methods of Birth Control**: Temporary methods of birth control, also known as contraception, are techniques used by couples to avoid pregnancy. These methods can include natural methods, barrier methods, hormonal methods, and more.

2. **Focus on Natural Methods**: The question specifically refers to temporary methods, particularly natural methods such as periodic abstinence and lactational amenorrhea. These methods do not involve any devices or medications.

3. **Periodic Abstinence**: One common natural method is periodic abstinence, where couples avoid sexual intercourse during the fertile window of the menstrual cycle, typically from the 10th to the 17th day when ovulation is most likely to occur.

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