6, 8, and 9 are all dependent clauses because you would not be able to say them on their own and make sense. They begin with words that make the listener expect more information in that sentence. For example if I just said "If I was taller" and said nothing else, the sentence wouldn't make much sense, so that makes it dependent.
7 and 10 are independent because you can say them on their own and it would make sense. I could say "I am taller" or "I wish I were taller', and the sentence would be complete
When we say participles, these are words which taken the verb forms both in the -ing form (present) and the -ed or -en form (past), but these function as adjectives only. So based on the given statement above, I can say that it is TRUE since participles can be used in order to shorten the subordinate clause. Hope this helps.
1. Don’t ride
2. Don’t sell
3. Doesn’t bring
4. Doesn’t take
5. Doesn’t cost
6. Don’t seem
7. Don’t buy
8. Doesn’t dance
9. Doesn’t run
10. Doesn’t work
11. Doesn’t eat
12. Don’t swim
13. Don’t ski
14. Doesn’t hurt
15. Don’t give up
Conflict and examine the list of characters. A good example is Romeo and Juliet, you would not have known who anyone was if you had not examined the list of characters.