NXT Introduction questions

1. Fill in the Blank
The heart of the NXT System is the NXT brick. Its a full 16bit microprocessor. You can plug sensors in along the _________ and motors in along the ___________.
Bottom, top2. Open-Ended
What are the four sensors it discusses and what do they measure?
The four sensors are; the light sensor which measures how much light is in the room, the ultrasonic sensor which measures distance, the sound sensor which measures sound levels, and the touch sensor which responds to press and release.3. Short Answer
How does the NXT Brick know how many rotations the motor has made?
The NXT Brick has a sensor that measures the speed and rotation per second of each motor plugged in to make sure that the motor does the correct command.4. Short Answer: Step-by-Step
How would I make the robot run the program I wrote? 
First power on the NXT brick then press the center button when the my files option in selected, next press the center button when the software files are selected, after that your programs will be listed in order of when they were uploaded, find the program you wish to run based on name and press the center button once you have selected the program you wish to run.5. Short Answer: Step-by-Step
How do I turn off the NXT brick?
Hold down the button which is under the center button then you should get the option to turn off then select yes then press the center button.