Final answer:
The advantage of salmeterol (Serevent) over other beta2 agonists is its longer duration of action.
Step-by-step explanation:
The advantage of salmeterol (Serevent) over other beta2 agonists such as albuterol (Proventil) is its longer duration of action. Salmeterol is a long-acting beta2 agonist (LABA) that works by relaxing the smooth muscles in the airways, providing a sustained bronchodilatory effect. This longer duration of action allows for less frequent dosing compared to short-acting beta2 agonists like albuterol.