Explanation

• The time and date are displayed on the system tray.
  
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• The system tray (or "systray") is a section of the taskbars in the Microsoft Windows operating system (OS) user interface that provides easy access icons to the user's most commonly used apps and displays the clock.
• A system tray is also available in other OSes such as Linux, Mac OS, Android, and iOS.
  

Explanation

Examples of conjunctions:

And, or, so, since, for, because, as, but, yet, still, while

Conjunctions are parts of speech that connect words, phrases, clauses, or sentences. 

Explanation

A "white elephant" refers to something that is useless and costly to maintain.

The term originates from the ancient practice of giving a sacred but burdensome white elephant as a gift, which could be expensive and impractical to care for.

Explanation

Explanation

"She is senior to me." 

This phrase correctly uses "to" to compare seniority or rank between individuals.

Explanation

"The sky is above our head".

It indicates the sky's position in relation to where we are.

It emphasizing that it is higher than us.

Explanation

Tetrafluoroethane (HFC-134a) is commonly used in modern refrigerators.

Unlike Freon, it does not deplete the ozone layer.

Explanation

The Colorado River is located in the USA.

It flows through seven states.

It is known for carving out the Grand Canyon.

Explanation

• She has been working since morning.
• This indicates that she started working in the morning and continues to do so.

Explanation

In the night, mysterious creatures prowl.

"In the night" is the correct phrase as it indicates the time during which the creatures are active.

"In" is used to specify periods of time during the day or night.