1) This is "a sentence within double-quotation marks preceded by a space and followed by a space"

2) This is "a sentence within double-quotation marks preceded by a space and followed by a comma",

3) This is 'a sentence within single-quotation marks preceded by a space and followed by a space'

4) This is 'a sentence within single-quotation marks preceded by a space and followed by a comma',

5) This is 'a sentence within single-quotation marks preceded by a space and followed by a period'.

6) This is 'a sentence within single-quotation marks preceded by a space and followed by a dash'-

7) This is 'a sentence within single-quotation marks preceded by a space and followed by a slash'/

8) This is'a sentence within single-quotation marks preceded by a letter s and followed by a letter x'x