Questions

A shell is an interactive user interface to an operating system services that allows an user to enter commands as character strings or through a graphical user interface. The shell converts them to system calls to the OS or forks off a process to execute the command. System call results and other information from the OS are presented to the user through an interactive interface. Commonly used shells are sh,csh,ks etc.

An ionic bond is a chemical bond between two atoms in which one atom seems to donate its electron to another atom.

Here in the given compounds, the compound that contains ionic bond is CaO, Calcium oxide.

Shipment movement information is captured each time a tracking label is scanned in the UPS delivery system. There may be several days between scans if the shipment is going cross-country or moving between countries.

Destination Scan: The shipment has arrived at the local UPS facility responsible for final delivery.

Arrival Scan: The shipment has arrived at a UPS facility.

Departure Scan: The shipment has departed a UPS facility and is on its way to the next UPS facility.

Origin Scan: UPS has received the shipment.

Nigeria, an African country on the Gulf of Guinea. 

Nigeria has a Federal Republic and Presidential system of Government.

Radio waves have much longer wavelengths and lower frequencies than do visible light waves. In contrast, X-rays have much shorter wavelengths and higher frequencies. 

Ultraviolet Light (UV). part of the electromagnetic spectrum that consists of waves with frequencies higher than those of visible light and lower than those of x-rays.