`ex1`
`1`. What is it?
→ What are they?
`2`. It is a couch
→ They are couches
`3`. That is a bookshelf
→ Those are the bookshelves
`4`. There is a lamp on the table
→ There are lamps on the table
`5`. He is a doctor
→ They are doctors
`6`. I am a student
→ We are students
`ex2`:
`1`. I live in Ho Chi Minh city
`2`. This is an eraser
`3`. What does she do?
`4`. There are four people in my family