Individual behavior would be Wearing a bike helmet and Social norms would be matched up with Speaking out against sexual assault.
Felling hopeless would be the answer.
The correct answer would be "avoiding body piercings and tattoos".
Two cells which are in direct contact can send signal to each other across gap junction. For cells which are not in direct contact, there is a number of ways through which these cells communicate, these basically include: paracrine signalling and endocrine signalling. In paracrine signalling, a cell secrete a chemical substance which have effect on a nearby cell while in endocrine signalling, hormones are released into the circulatory system, which convey them to the target cells.
