Q 1 : Animals all need water. They may die without it. Animals all need water, but they may die without it. Animals all need water or they may die without it. Animals all need water when they may die without it.
Q 2 : My brother wants to win the trophy. I want to win the trophy. My brother, but I want to win the trophy. My brother or I want to win the trophy. My brother and I want to win the trophy.
Q 3 : Dolphins live underwater. Sharks live underwater. Dolphins, but Sharks live underwater. Dolphins and Sharks live underwater. Dolphins or Sharks live underwater.
Q 4 : The sun came out. The day was still cold. The sun came out after the day was still cold. The sun came out or the day was still cold. The sun came out, but the day was still cold.