Here are the sentences with more appropriate synonyms:
7. Not wearing a seat belt can "cause" injuries.
8. Our sweaters are "similar" except that mine is blue rather than green.
9. The angry workers went out on strike to "demand" a wage increase.
10. After four hours the exhausted runners "limped" across the finish line.
11. Pollution will continue to "increase" unless we take more steps to control it.
12. When the power went off around the city, our street became absolutely "dark."