Read and select the correct option to complete the text

*. READING
Part 6: Read and select the correct option to complete the text. (1pt)
In the future, there will be many new (21) _______ of transportation. People may travel by
flying cars or hot air balloons. (22) _____, at the present, a company is designing an electronic train.
This train will have very little emission because it runs (23) solar energy. It uses solar panel
windows to generate electricity, so it can help the environment. This electronic train can carry up
to 10,000 (24) and it will be able to travel a distance of 600 kilometers in one hour. The price
is 300 dollars for three people, not (25) _____ as a tram, but people can travel to different places
faster.
21. A. ways
22. A. However
23. A. with
24. A. pedestrians
25. A. more cheap
B. means
B. Therefore
B. by
B. travellers
B. such cheap
C. methods
C. Otherwise
C. on
C. drivers
C. as cheap
D. devices
D. Though
D. in
D. passengers
D. little cheap