1. Nam didn't go to work yesterday………because of …......his illness.
2. The book .........which..... is on the table belongs to my brother
3. Our little son was sleepy when we were walking to the park;…therefore …., we went home early.
4. The teacher asked Van …… if…… she had ever tried calling a helpline.
5. It’s necessary for secondary students …… to……. wear uniform today
6. Nobody can deny the benefits of the Internet in our life,…can……..they?