Help me plzz i neeed help

Ihave a singular monitor that is a tv for my computer. recently, i took apart my computer and put it back together. when i put in the hdmi cord and booted the computer to see if it worked, the computer turned on fine but the screen was blue with "hdmi no signal." i've tried everything that doesn't require buying spare parts, any answer is appreciated!

What key should you press and hold to select and open multiple files at one time? enter alt control esc

Per the municipal solid waste report, what are the most common sources of waste (trash