Sometimes I get a tingly feeling at the back of my head/brain whenever a talk to certain people and I don't know what is means. Can you help me?

What a self improvement for a busy person who had difficulty finding time to exercise/ dropping out of clubs and activities/ refusing social invitations from friends/ scheduling daily invitation activity/ sleeping fewer hours at night

The bones of the extremities are parts of the a-appendicular skeleton b-axial skeleton c-long bone group d-medial skeleton

*edit* i took the test and i picked a and it was incorrect for its c! rank the following suggestions for preventing std, in order of increasing effectiveness. 1) using latex condoms properly 2) using spermicidal foam or jelly with a monogamous partner 3) abstaining from sexual intercourse and genital contact a. 1, 2, 3c. 2, 1, 3