This is the shape most Class D airspaces take on a sectional chart.
What is a cylinder or circle?
Before taxiing for departure at a Class D airport, you must first contact this position.
What is Ground Control?
What is the field elevation of this Class D airport?

What is 6 feet msl?
San Carlos has a VASI. This is what it stands for.
What is visual approach slope indicator?
This is the taxiway that you are currently on.
What is taxiway alpha?
Class D airspace typically extends from the surface up to this altitude above airport elevation.
What is 2,500 feet AGL?
The four things you must always include when making a radio call.
What are who you’re calling, who you are, and where you are, and what you want?
The star after the CT frequency indicates this.
What is the control tower operates part-time?
This is what "B" stands for after the number 6.
What is a beacon?
This is the name of the "arrowed" area before the official start of the runway.
What is displaced threshold?
You must establish this with ATC before entering Class D airspace.
What is two-way radio communication?
When calling tower, this phrase indicated you are ready for takeoff.
What is "ready for departure"?
This is what the number twenty signifies in the blue box.
What is the ceiling of the class delta airport?
Both runways have REIL. This is what it stands for.
What is Runway End Identifier Lights?
This indicates what?
What is the amount of runway remaining?
When the tower closes, Class D airspace usually reverts to this type of airspace.
What is Class E (surface) or Class G, depending on local regulations?
ATC will respond with this phrase to confirm two-way communication has been established.
What is repeating your call sign?
What do the "pegs" extending out of the airport signify?
What is fuel is available here?
This is what OX 2 signifies.
What is oxygen is available at this airport?
This is the name of the marking.
What is taxiway holding position marking?
Generally speaking, a class delta has a radius of this many statute miles.
What is five?
When leaving Class D airspace, you should remain on the tower frequency until this instruction is given.
What is “frequency change approved”?
When performing touch-and-goes on Runway 12, which traffic pattern will we use?
What is a left/standard traffic pattern?
During daylight savings, at which local time does this airport close?

The "arrowed" area allows for these operations, but not this one specific operation.
What is taxi and takeoff, but not landing?