Answer:
Mary is an ex-teacher from Lincoln High.
Thirty-three students went to the tournament.
Tom liked to read about pre-Roman times.
Explanation:
A "hyphen" is a punctuation mark that is used to join words. They may be used in different ways. For example, when two words act as a single idea such as modifying a noun, then they are hyphenated. For example "pre-Roman." This is an adjective which modifies the noun "times."
Compound numbers (such as two-word numbers) are also being hyphenated when written as words. For example: "Thirty-three."
You also have to use hyphen when a word starts with prefix all, ex, etc. For example: ex-teacher.
Additional Information
Remember that when you are dividing words at the end of a line, one-syllable words like the word "book" cannot be divided.
