Use the adjective in brackets in their correct forms of comparison to complete the sentences. (So sánh hơn)

1.Tea is .................than coffee (cheap)
2.The new harvest machine ...................than the old one .(effective)
3.The countryside is .........................than the town .(beautiful)
4.A tractor is ..................than a buffalo.(powerful)
5.My sister is ................than me.(tall)
6.Blue whales are .....................................than elephants.(heavy)