Questions

In computing, ".bak" is a filename extension commonly used to signify a backup copy of a file.

The halogens make up group 17 in the periodic table.

They are five elements:

Chlorine (Cl)

Fluorine (F)

Bromine (B)

Iodine (I)

Astatine (At).

But astatine is not purely halogen as it is radioactive.

The Qatar Airways has launched the World’s longest scheduled commercial service to ply between Doha to Auckland. The inaugural service of Flight QR920 took off on February 5, 2017 from Doha and will take 16 hours and 20 minutes to travel 14,535 kilometers to reach Auckland in New Zealand.
This makes Qatar Airways to launch the World’s fastest and longest passenger service in terms of flying time. Prior to this, emirates launched the world’s longest non-stop scheduled commercial flight with a service from Dubai to Auckland, spanning 14,200 kilometres.