Explanation

• Sound travels fastest in diamond,
• With a speed of approximately 12,000 meters per second (m/s).
• Because sound travels fastest in stiff, dense materials

Additional information 
The speeds of sound in different materials:

• Air: 343 m/s
• Water: 1433 m/s
• Wood: 3300-3600 m/s
• Brick: 4176 m/s
• Steel: 6100 m/s
• Diamond: 12000 m/s

Explanation

ٹیسٹ کی تیاری کے لیے بار بار پیپرز میں آنے والے سپیلنگ ضرور یاد کریں

Click here

Explanation

Avast and NAV are anti-virus software

***

Symantec's Norton Group launched Norton AntiVirus 1.0 (NAV) for PC and compatible computers.

***

Avast's free antivirus software detects and blocks all types of malware in real-time to prevent them from infecting your computer.

Kaspersky, Norton, and Avast are anti-virus software

Linux is an operating system, not an anti-virus

Anti virus 

Explanation

• The main window in a computer spreadsheet is called a workbook
• while 
• The title bar in MS Excel displays the name of the  worksheet
• **
• In Excel, when we create a new document, we always select a blank workbook, as you already have done in the previous chapter.
• When this blank workbook opens up, an interface you see is called a workbook window.
  

Explanation

The sentence structure "had been + verb (-ing)" indicates the Past Perfect Continuous Tense.

This tense is used to show an action that started in the past and continued for a certain duration before another past event.

Explanation

 In 2010, the estimated population of Pakistan was approximately 173.51 

Explanation

 Sri Lanka is a significant exporter of textiles and garments

Additional information 

 Sri Lanka Capital is Colombo.

Sri Lanka Currency is Sri Lankan Rupee.

Sri Lanka official language is Sinhala; Tamil.

Sri Lanka located is in Continent Asia.

Explanation

 I am here for you.

Correct and natural — This is the standard, meaningful phrase that means “I am present and available to support you.”

Explanation

"The committee is meeting tomorrow."
"Committee" is a collective noun and is treated as singular in American English, so it takes "is".

Explanation

Euphoria جوش means a state of intense happiness خوشی  or excitement.