【简答题】在极低温状态下,有些金属电阻突然变为零的现象叫 _________________ 现象。
【简答题】The first bicycles were made of wood. After that, manufacturers used steel tubes. But the steel ones cost too much. The people in poorer countries want to have cheaper ones. Izhar Gafni had an idea to...
【单选题】速降系统包括四个部分,下列不属于速降系统的是( )。
【判断题】链传动的平均传动比和瞬时传动比都为常数。( )
【单选题】The problem with the American car manufacturers is ______________.
A.
their products are of lower quality
B.
their products are not liked by the Japanese
C.
they don’t send salespeople to door-to-door selling
D.
their products are too expensive
【单选题】设函数 ,曲线 处的切线方程为 ,则曲线 处的切线方程为 ( )
【单选题】不宜直接添加入面包面团中的乳品是( )。