Choose the word or phrase (A, B, C or D) that best fits the space in each sentence
1. ___________ is a source of non-renewable energy.
2. In the 1800s, streetcars ___________ a popular means of transportation in cities.
3. ___________ will the hoverboard travel? – It will travel at 40 km/h.
4. A self-driving car can move ___________ itself.
5. You’re driving too fast. There’s a ___________ on this road.
6. ___________ will a flying car cost?
