Have is used only in the Present Simple when it means possess. Think is only used in the Present Simple when it means believe.
1. Look! The boy (cross) the river alone.
2. Listen to those girls. What ...they (talk) about?
3. Look! the mango (fall).
4. I always (go) to bed after midnight.
5. I (believe) in God.
6. Can you change the bulb? It (blink).
7. Run ! The dog (run) after you.
8. Throw the life ring to the man. He (drown).
9. The River Nile (flow) into Mediterranean.
10.The car (belong) to me.