Punctuation, Part 2

Apostrophe

• Do not use apostrophe to make numbers, letters, and abbreviations plural For example "1920s not 1920's"
• don't use apostrophe for letter unless it is lower case. Other ways you can use italics. For example " Js, js"  Exception for A and I so confusion is not caused "A's, I's"
• Avoid misusing apostrophe, make sure the word is always possessive.

Quotation marks 

• when using quotation within quotation only use the single quotation marks
• use them around titles of short works
• use them to set off words used as words ( The words "accept" and "except" are frequently confused
• use comma before quotation when introducing a quote said by someone 

Other punctuation Marks 

• To use a dash use to hyphens, they are used to separate material that needs emphasis 
• Dashes can be used to set off appositives that contain commas and introduce list
• Parenthesis are used to enclose extra information. They can also be used while numbering a list in writing form.
• Brackets  should be used to enclose information inside of a quote
• Slashes are used to separate a couple lines in poetry 

Evidence 

TMT officials have said that " they have sought to minimize the project’s environmental effects by choosing a site where fewer animals might be affected, building a double-walled septic tank to handle all wastewater, and committing to using less hazardous chemicals in the observatory." (Hofschneider, Anita.)

When integrating quote I need to place a comma after "that"

"That's why this thirty meter telescope is so important. It may lead us to new information that can revolutionize the future.…."

The apostrophe he is used correctly but I feel that it would be better to say "That is" instead of "That's" in this situation