Which device containing sensors send signals to the computer whenever light changes are detected?  A. Light pen

B. Reflectors

C. Deflector

D. All the above​

Designing a mobile web page is a little different from designing a regular web page. name at least three features that should be considered when designing a website that is mobile phone-friendly, and briefly explain why they are important.

Which network media uses different regions of the electromagnetic spectrum to transmit signals through air? uses different regions of the electromagnetic spectrum to transmit signals through air.

Facial expressions and gestures are examples of messages.