Sure! Here are the completed sentences:

1. I‘ve decided (**stop**) **to stop** smoking.
2. I (**visit**) **visited** Singapore two years ago.
3. Look at those black clouds. It (**rain**) **is going to rain**.
4. We are tired of (**work**) **working** for low salary.
5. This is the second time you (**break**) **have broken** a cup.
6. (**you/do**) **Have you done** the homework yet?
7. Mai is in her room. She (**play**) **is playing** the guitar.
8. The teacher said that we should (**not make**) **not make** noise in class.
9. Water (**cover**) **covers** most of the Earth’s surface.
10. The gate (**lock**) **is locked** at 6.30 p.m every day.