118 English Grammar Demystifi ed
Written Practice 5-10
Read the following paragraphs. Use all that you have learned about punctuation to
correct the sentences. The sentences are numbered for clarity in the Answer Key.
Paragraph 1
- High school students know all about the Hubble Space Telescope in fact they
can’t even remember a time when it wasn’t there. 2. The Hubble was launched in
1990 and it has already outlived its expected 15-year life span in addition it has seen
its fi fth and fi nal repair mission.
Paragraph 2
- Hubble entered our lives in the 1990s its advent paralleled the enormous growth
in access to the Internet as a result everyone’s computer was capable of bringing the
magnifi cent images of the universe up close. 2. However Hubble is much more than
pretty pictures interestingly it has generated more research papers than any other
scientifi c instrument. 3. Before Hubble astrophysicists could never agree on the age
of the universe some had said it was 10 billion years old while others had said 20
billion. 4. Hubble did the correct calculations our universe was born 14 billion years
ago. 5. Hubble accomplishments include the following measuring the age of the
universe, discovering that the Milky Way has a massive black hole in its center, and
uncovering the role of “dark energy” in an expanding universe.
Apostrophe
For a very small mark of punctuation, the apostrophe can cause a big problem. You
need to use it correctly for clarity, and here are the rules you need to know.
HOW TO USE AN APOSTROPHE
Use an apostrophe to show the omission of a letter. In the following three examples,
the o’s are omitted.
You weren’t (were not) expected until noon.My other friend isn’t (is not) coming.There aren’t (are not) enough days in a New England summer.