Mention any two purposes of using comments while designing a HTML webpage.

Twisha has got confused with a few tags and their attributes. Help her match the tag with correct attribute.

Write suitable html statements to display the following text on a webpage in appropriate subscript and superscript form:

a. CO₂

b. X²

Ronaldo, a web designer in a start-up company, wants to give headings in a webpage through <h1> tag. Additionally, he wants to implement following styles on all the <h1> tag of the same webpage at one go.

• Color-blue
• Background color-yellow
• border of the heading - 2px in red

He is not able to implement the above-mentioned additional styles of <h1> tag through regular html code. Suggest him a way out and also help him in writing the code for same.