With reference to the use of Punctuation marks, which of the following statements is not correct?
1
A comma is not needed before 'and' when it joins two words or phrases (not clauses).
2
A period (.) is used at the end of a declarative sentence.
3
A dash (—) is longer than a hyphen (-) and can be used to indicate a pause or break in thought.
4
An apostrophe is used to form the plural of numbers or letters.