The video begins with an expression of gratitude and introduces the topic with a brief mention of 'Crystal'.

What is the initial expression used in the introduction?

• Welcome

• Good Morning

• Hello World

• Thank God

What is the duration of the 'Thank God' section?

• 600 milliseconds

• 450 milliseconds

• 510 milliseconds

• 540 milliseconds

What is the main topic discussed in the second section?

• Stone

• Glass

• Crystal

• Diamond

Which of the following is NOT mentioned in the transcript?

• Thank God

• Crystal

• Hello

• None of the above

How long does the 'Crystal' section last?

• 510 milliseconds

• 450 milliseconds

• 600 milliseconds

• 540 milliseconds