Read the following passage and mark the letter A, B, C, or D to indicate the correct answer that best fits each of the numbered blanks.

Travel is something which people do every day. It is very difficult to avoid the (21) ____________ to travel. It may be a trip to school, university or to work. Travelling can often take a long time, especially when great distances need to be covered. People often (22) ____________ travelling abroad for holidays. But for some people, travelling is not fun at all. Some people suffer from travel sickness. This means that they will (23) ____________ very unwell each time they travel.
Travelling can be either affordable or costly. It often depends on (24) ____________ far you want to travel and the choice of transport. People who need to travel short distances may choose not to use any transport at all. People often rely on their legs to take them to places nearby. This is often (25) ____________ as certain modes of transport have been said to produce harmful emissions and damage the environment.