There are several types of fiber optic connectors available today. The most common are: ST, SC, FC, MT-RJ and LC style connectors.

All of these types of connectors can be used with either multimode of singlemode fiber.

There are three types of polishes which can be applied to a fiber connector: PC or Physical contact, UPC or Ultra Physical contact and APC or Angled Physical contact.

Each polish type exhibits a different level of back reflection. Back reflection is a measure of the light reflected off the end of a fiber connector. This light is measured in decibals.

For certain applications, the amount of back reflection on a fiber connector is critical.

Lesson 1, Text 1: "Quick Story Of Thermometer. , Exercises.

• What are the texts about? 
• Who invented the first thermometer?
• Who invented the first reliable mercury thermometer in 1714??

Write a opinion about the last text "quick story of thermometer" in 100 words.