One should be aware of Twitter etiquette. To be taken seriously ...

[gbarreiro]

One should be aware of Twitter etiquette. To be taken seriously as a professional commentator on this type of social media.
 
  a. One should be aware of Twitter etiquette, to be taken seriously as a professional commentator on this type of social media.
  b. One should be aware of Twitter etiquette, to be taken seriously as a professional commentator. On this type of social media.
  c. One should be aware of Twitter etiquette, to be taken seriously. As a professional commentator on this type of social media.
  d. None of the above

Question 2

Original Sentence: Not everyone is anxious to get a tattoo, so semicolon T-shirts can be purchased at Project Semicolon's official online store instead. Possible Edits:
 
  a. Not everyone is anxious to get a tattoo, for semicolon T-shirts can be purchased at Project Semicolon's official online store instead.
  b. Not everyone is anxious to get a tattoo, nor semicolon T-shirts can be purchased at Project Semicolon's official online store instead.
  c. Not everyone is anxious to get a tattoo, yet semicolon T-shirts can be purchased at Project Semicolon's official online store instead.
  d. Correct as is.

[lauravaras]

Answer to Question 1

a
RATIONALE: A fragment is an incomplete sentence. It is missing a subject or verb and therefore cannot be a complete thought.

Answer to Question 2

d
RATIONALE: To choose the correct answer, review the relationship between the two complete sentences on each side, and then determine which coordinating conjunction to place after the comma.

[gbarreiro]

TYSM

[momolu]

Gracias!