Question

2.Traveling by air is much more expensive than traveling by train

->Traveling by train............................................

Answer 1

7. Travelling by plane is much more expensive than traveling by train.
→Travelling by train is cheaper than traveling by plane .

mình nghĩ traveling là travelling mới đúng

Answer 2

2.Traveling by air is much more expensive than traveling by train

->Traveling by train is much cheaper than traveling by air.