What effect will most likely result from a combination of drug abuse and unprotected sex with different partners? increased risk of developing a sexually transmitted infection
decreased chance of developing cervical cancer
decreased risk of developing HIV infection
increased risk of unplanned pregnancy

Increased risk of developing a sexually transmitted infection

Explanation:

Drug abuse typically means that the person would most likely be under influence, and therefore cannot think properly during that set duration.

Unprotected sex typically means that there is no protection at all from STDs if one or both of the partners have STDs currently.

Different partners means that there is a higher chance of obtaining STDs from one or more of the partners.

Therefore, your answer should be increased risk of developing a STD.

tell their parents and make sure she gets from a counselor or therapist. be supportive and be there for her. be a kind and good friend. spend time with her to make her feel like she's not alone. i'm not a professional but i really hope they stays strong.