`a)` The Nile is the longest river in the world.
`b)` Lan is the tallest student in my class.
`c)`English coffee is the worst of all.
`d)` Australia is the smallest continent in the world.
`e)` That is the highest mountain in the world.
Vì ta có: Form
`\text{S + tobe + the + short adj/adv + est + in + O/A}`
`\text {S + tobe + the most + long adj/adv + in + O/A}`
