( )13.
( )14.
( )15.
C
( )14.
B
( )15.
B
答案：13. C；14. B；15. B
(
A. In 1789. B. In 1781. C. In 1791.
(
A. He learned English.
B. He worked with his father.
C. He studied engines.
(
A. He began to learn English.
B. He became his father's helper.
C. He wrote his own name for the first time.
(
A. For 8 hours. B. For 12 hours. C. For 13 hours.
(
A. The plane. B. The car. C. The train.
A
)16. When did George Stephenson start to work?A. In 1789. B. In 1781. C. In 1791.
(
C
)17. What did George Stephenson often do on holidays?A. He learned English.
B. He worked with his father.
C. He studied engines.
(
A
)18. What did George Stephenson do when he was seventeen?A. He began to learn English.
B. He became his father's helper.
C. He wrote his own name for the first time.
(
B
)19. How long did George Stephenson work every day?A. For 8 hours. B. For 12 hours. C. For 13 hours.
(
C
)20. What was the greatest invention that George Stephenson had invented?A. The plane. B. The car. C. The train.
答案：16.A 17.C 18.A 19.B 20.C
(1)
(2)
Marie Curie
(2)
Twice
答案：.(1)Marie Curie.
(2)Twice.