【简答题】Questions 19 to 21 are based on the passage you have just heard. 第19题:
【简答题】19-22Questions 19 to 22 are based on the conversation you just heard. 第19题:
【单选题】以下关于工程中的常见约束的说法中,错误的是
A.
柔绳约束与链条约束类似,约束力只能沿着绳索的方向背离被约束的物体;
B.
光滑铰链约束和光滑球铰链约束本质上都是光滑接触约束,约束力其实只有一个;
C.
光滑接触面约束对应的约束反力,其方向沿着接触处的公法线而指向被约束的物体;
D.
光滑圆柱铰链约束包含向心轴承、活动铰链支座、固定铰链支座、光滑球铰链等。
【单选题】名句“雄关漫道真如铁,而今迈步从头越”出自()的手笔
【简答题】19-21 Questions 19 to 21 are based on the conversation you just heard. 第19题:
【单选题】Questions 19 to 22 are based on the conversation you have just heard.19.
B.
It improved operations.
C.
Operations became less efficient.
D.
The employees became dissatisfied.