66. Garrett A. Morgan was an67. Garrett A. Morgan liked to make68. When did Garrett A. Morgan leave school?69.70. 相关知识点: 试题来源: 解析 66. American 67. new things 68. He left school at the age of 14./ At the age of 14. 69. How were traffic lights born? 70.让交通...
At what age did Janet Emerson Bashen make LinkLine? At what age did Elizabeth Freeman have her first child? How old was Catherine II when she was married to Peter III? Who was Daniel Morgan married to? How old was Catherine Parr when she died?
The first electric traffic light had only red and green lights; it did not have a yellow light like modern-day traffic signals. Instead of a yellow light, it had a buzzer sound that was used to indicate that the signal would be changing soon. The First Four-way And Three-colour Traffic...