English Skills with Readings 7th Edition by John Langan

Exercise 14

In the following sentences, place a comma before each joining word that connects two complete thoughts (two subject-verb combinations). Do not place a comma within the sentences that have only one subject and a double verb; label these as "correct."
1. The oranges in the refrigerator were covered with blue mold and the potatoes in the cupboard felt like sponges.
2. All the pants in the shop were on sale but not a single pair was my size.
3. Martha often window-shops in the malls for hours and comes home without buying anything.
4. Tony left the dentist's office with his mouth still numb from Novocain and he talked with a lisp for two hours.
5. The whole family searched the yard inch by inch but never found Mom's missing wedding ring.
6. The car squealed down the entrance ramp and sped recklessly out onto the freeway.
7. No one volunteered to read his or her paper out loud so the instructor called on Amber.
8. The aliens in the science fiction film visited our planet in peace but we greeted them with violence.
9. I felt like shouting at the gang of boys but didn't dare open my mouth.
10. Lenny claims that he wants to succeed in college but he has missed classes all semester.