问题
单项选择题
能耗制动的主要缺点是（）。
A、消耗直流电能
B、制动设备复杂
C、低速的制动转矩小
答案
参考答案：C
搜题请搜索小程序“爱下问搜题”
能耗制动的主要缺点是（）。
A、消耗直流电能
B、制动设备复杂
C、低速的制动转矩小
参考答案：C
| Close test. (完形填空) | |||
| Helen Keller was a very bright, beautiful girl. 1 the age of six months, she could already say a few words. But when she was two years old, she got badly ill. She could not see or hear, and soon she could not even talk. Since then Helen had to fight for 2 she wanted. When she was six, her parents invited a teacher for her. 3 the help of the teacher, she began to see and hear the world around her through her 4 . She learned to read books for the blind. The teacher took Helen for long walks, and 5 her about all the beautiful sights (风景). Helen 6 flowers, climbed the trees and smelled a rain storm (暴风雨) before it came. She also learned how to swim and 7 a horse. After she 8 , she became a famous writer in America. Her first and most famous 9 is The Story of My Life. Her story has 10 new hope to many blind and deaf (聋的) people. It has given light to those in darkness and encouraged (鼓舞) them to live and work. | |||
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