What is the title of senator who acts in the absence of the actual president of the senate?

What is the role of institutions in society - do they perform positive functions, or simply work in the interests of the powerful and against the powerless? (a related question here is why do our life chances vary by class, gender and ethnicity)

Figure out who is lying and telling the are 2 truth telers and 3 liarsperson a says person e is lyingperson b says person c is lyingperson c says person b id lyingperson d says person b is telling the truthperson e says person c is telling the truth

What was the main purpose of one of the first world organizations