1) Define Bluetooth technology. Bluetooth technology is a wireless communication standard that allows devices to connect and exchange data over short distances using radio waves. It is commonly used for connecting devices like smartphones, headphones, and other peripherals. 2)How to write comment in XML? In XML, you can write comments by enclosing the text within <!-- and -->, like this: <!-- This is a comment in XML --> 3) What is Android Virtual Device? An Android Virtual Device (AVD) is an emulation of an Android device, created and managed by the Android Emulator. It allows developers to test and run Android applications on a computer without the need for physical hardware. 4) Listout declaration rules of XML. Declaration rules in XML: XML documents must have a single root element. Element names are case-sensitive. Attribute values must be enclosed in quotes. Nesting of elements should be well-formed, with proper opening and closing tags. Special characters like <, ...