【简答题】Hotel receptionists, like hostesses in a restaurant, are the first contact a person has when entering an establishment. A hotel receptionist gives a first impression of the entire hotel. Attentive , p...
【单选题】梁的变形叠加原理适用的条件是:梁的变形必须是载荷的线性齐次函数,要符合此条件必须满足 要求。
C.
( C )梁的变形是小变形,且梁内的正应力不超过弹性极限
D.
( D )梁的变形是小变形,且梁内的正应力不超过比例极限
【单选题】梁的变形叠加原理适用的条件是:梁的变形必须是载荷的线性齐次函数,要符合此条件必须满足()要求。
C.
梁的变形是小变形,且梁内的正应力不超过弹性极限
D.
梁的变形是小变形,且梁内的正应力不超过比例极限
【单选题】In the hotel, receptionists ask about reservation by saying some sentences like this:
A.
Do you have a reservation, please?
B.
Could you tell me your name, please?
C.
Could you spell your name, please?
【单选题】下列说法正确的是 [ ]
A.
若f′(x 0 )不存在,则曲线y=f(x)在点(x 0 ,f(x 0 ))处就没有切线
B.
若曲线y=f(x)在点(x 0 ,f(x 0 ))处有切线,则f′(x 0 )必存在
C.
若f′(x 0 )不存在,则曲线y=f(x)在点(x 0 ,f(x 0 ))处的切线斜率不存在
D.
若曲线y=f(x)在点(x 0 ,f(x 0 ))处的切线斜率不存在,则曲线在该点处就没有切线
【单选题】若曲线y= 在x 0 处存在切线,则 必存在。( )