1. The belligerent dog barked loudly, but I was not frightened.
2. Abby and David skateboarded on the asphalt, yet neither of them was injured.
3. The colonel lieutenent corporal and general all headed toward the plane. (no comma needed)
4. Gilly hope to join the team, so she practiced every night after class.
5. His school is in Austin Texas. (no comma)
1. My friends want an apology for my behavior; I see no need for one.
2. My cousin asked to see the manager; there was a large discrepancy in the bill.
3. Summer is coming take out the barbeque grill! (no semicolon)
4. Spring is the best time of year; flowers are a welcome sight after the snow.
5. The pilot had traveled to Honolulu, Hawaii Hamilton, Bermuda Mumbai, India and Melbourne, Australia. (no semicolon)
Hope this helps :)