Final answer:
Abstinence is the most effective method to prevent STIs and unwanted pregnancies, while condoms and communication with partners are also important.
Explanation:
Abstinence is the most sure-fire way to avoid STIs or unwanted pregnancies as it involves refraining from engaging in sexual behaviors. While condom use can reduce the risk of STI transmission and pregnancy, it is not 100% foolproof. Proper communication with your partner about sex is essential for practicing safer sex and making informed decisions.
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