In addition to the call buttons, elevators usually have floor indicators (often illuminated by LED) and direction lanterns. The former are almost universal in cab interiors with more than two stops and may be found outside the elevators as well on one or more of the floors. Floor indicators can consist of a dial with a rotating needle, but the most common types are those with successively illuminated floor indications or LCDs. Likewise, a change of floors or an arrival at a floor is indicated by a sound, depending on the elevator.
What generally indicates the arrival of the elevator at a new floor?
a sound

Amtrak's Northeast Corridor and Chicago lines originate at South Station, which serves as a major intermodal transportation hub, and stop at Back Bay. Fast Northeast Corridor trains, which serve New York City, Washington, D.C., and points in between, also stop at Route 128 Station in the southwestern suburbs of Boston. Meanwhile, Amtrak's Downeaster service to Maine originates at North Station, despite the current lack of a dedicated passenger rail link between the two railhubs, other than the "T" subway lines.
Where do Amtrack's Northeast corridor and Chicago lines end?
Back Bay

The Union Internationale des Associations d'Alpinisme (UIAA) has defined a list of 82 "official" Alpine summits that reach at least 4,000 m (13,123 ft). The list includes not only mountains, but also subpeaks with little prominence that are considered important mountaineering objectives. Below are listed the 22 "four-thousanders" with at least 500 m (1,640 ft) of prominence.
What group defined a list of 82 official Apline summits that reach 4,000m?
Union Internationale des Associations d'Alpinisme (UIAA)