【单选题】Jane is willing to pay $50 for a pair of shoes. The actual price of the shoes is $30. Her consumer surplus on this pair of shoes is
【单选题】影响带传动工作能力的说法,以下哪个是正确的?
A.
适合的张紧力以及大的带轮包角,能产生更大的摩擦力
【单选题】使执行元件平稳地由运动状态转换成静止状态的回路是( )回路。
【单选题】This pair of shoes very expensive.
【单选题】This pair of shoes from England
【简答题】This pair of shoes cost me 260 yuan.英译汉
【单选题】This pair of shoes made in Nanjing