A: 2
B: 3
C: 1
D: None
举一反三
- How many dimension figures are missed in the given drawing?[img=399x264]1803a0e7a6ba61d.png[/img] A: 2 B: 3 C: 1 D: None
- How many standard parts are there in the given assembly drawing? (Single option: 10 points)[img=452x314]1803a0e667962ff.png[/img] A: 3 B: 2 C: 1 D: 4
- Which drawing is not the cabinet drawing?[img=418x113]1803a0d98909c62.png[/img] A: (2) B: (1) C: (3) D: None
- As to the relationship between language and culture， how many metaphors are given in this video？（ ） A: 1 B: 4 C: 2 D: 3
- Choose cabinet drawing in the following figures.[img=354x113]1803a0d99e75604.png[/img] A: (4) B: (3) C: (2) D: (1)
内容
- 0
Let [img=106x27]1803e24b380ed67.png[/img] and [img=74x27]1803e24b40978a7.png[/img]. Then how many [img=8x23]1803e24b495bcd2.png[/img] satisfy [img=161x49]1803e24b5377bc8.png[/img]within [img=53x25]1803e24b5be23c8.png[/img]? A: 0 B: 1 C: 2 D: 3
- 1
已知随机变量E(X)=4,Var(X)=16/3，若[img=236x29]1803b3be51e276e.png[/img]成立，根据切比雪夫不等式， 此时a的取值范围是 A: 1≤a≤2 B: 1/2≤a≤3/4 C: 0<a≤1/3 D: 1/3< a≤2/5
- 2
设随机变量(X,Y)在区域｛(x,y): 0<|y|< x <2｝内均匀分布，则以下结果正确的是 A: 当0<x<2时，[img=96x25]1802dded7db6eef.png[/img]. B: E(X)=4/3 C: 当0<|y|<2时,[img=105x45]1802dded872b92f.png[/img]. D: P(X<1)=0.5 E: 当0<x<2时,[img=110x45]1802dded915de6e.png[/img]. F: E(X)=2/3 G: 当0<y<2时，[img=95x43]1802dded9a54300.png[/img].
- 3
The circuit is shown as Figure,how many current sources are there in the figure( )[img=536x645]1803a2c16457c15.png[/img] A: 2 B: 3 C: 4 D: 5
- 4
矩阵[img=117x63]18034e621c98abd.png[/img]的三个特征值是（ ）. A: 1, 4, 0 B: 2, 3 , 0 C: 2, 4, 0 D: 2, 4, -1