题干

出行是人们工作生活必不可少的环节,出行的工具五花八门,使用的能源也各不相同。某品牌电动自行车的铭牌如下:
车型:20吋(车轮直径:508 mm)
电池规格:36 V  12 Ah(蓄电池)
整车质量:40 kg
额定转速:210 r/min(转/分)
外形尺寸:L 1800 mm×W 650 mm×H 1100 mm
充电时间:2~8 h
电机:后轮驱动、直流永磁式电机
额定工作电压/电流:36 V/5 A
根据此铭牌中的有关数据,可知该车的额定时速约为(   )

A:15 km/h

B:18 km/h

C:20 km/h

D:25 km/h

上一题 下一题 0.0难度 选择题 更新时间:2018-12-09 08:22:17

答案(点此获取答案解析)

C

同类题4

选择最恰当的单词或词语,完成短文

    Former Presidents (前任总统) in the United States continue to receive special government services and money after their presidential term (总统 任期) ends. Each former president receives retirement pay, money to pay travelling expenses and money to pay the people who continue to work for them. They also get security 1 for the rest of their lives.

    Some former presidents seem to have 2from public life. But others continue to make contributions (做贡献) to the society.

    Former President Jimmy Carter is well known for his earnest devotion (热诚的奉献) since he left office. He helps build homes for poor Americans and helps settle international disagreement. And he has written several books. Many people have called Carter an example of a successful former president. Some experts note that public approval (公众的赞许) of Carter increased several years after his defeat in the presidential election (总统大选) of 1980.

    3 the opposite happened to former president Ronald Reagan. His popularity fell after he left office. Many people criticized him for4 an offer from a wealthy Japanese publisher to visit Japan. There he was paid about two million dollars just to make a few appearances. In 1994, Reagan began to suffering from Alzheimer's disease (老年痴呆症) and died ten years later.

    Former President George Bush has made few 5 appearances since leaving office. Recently, however, he and former President Bill Clinton have traveled together to places in need of aid following natural disasters.

    Bill Clinton is one of the most active former presidents. He makes speeches around the world. He wrote a best-selling book about his life. And he has set up a foundation that offers various 6 to people in need, including providing low cost medicines for people with AIDS around the world.