Lucency is a technical term for an area that lets x-rays through tissue and appears darker on the picture. Peri-screw lucency is a result of having had a peri-screw insert â¦ ed into the bone, possibly due to an accident.1 person found this useful. They're is a contraction or shortening of 'they are'.   . Their means belonging to people or things previously mentioned or  easily identified (Your parents do not look similar, except for  their noses).
Amplified antennas are best for the suburbs and rural areas, where a TV signal has to travel a greater distance. They also tend to perform better in rainy or stormy conditions, which can also affect how well a signal travels.
MAST MOUNTED PREAMPLIFIERS. Chapter Eight-TV ANTENNA-MOUNTED AMPLIFIERS. A mast or TV antenna-mounted amplifier (preamp) is used primarily to eliminate snow on the TV screen.Snow is actually electrical noise that is generated by the TV receiver and other electrical devices.he preamp itself is mounted on the TV antenna boom or on the mast as close to the TV antenna as possible. The power supply unit is mounted indoors. Power is supplied to the preamp unit through the transmission line.