在一节综合实践课上,五名同学手工作品的数量(单位:件)分别是:3,8,5,3, 4,则这组数据的中位数是( )件。
4
阅读理解。
One day Peter says to his mother, " Mum, everyone in our class says I have a big
head." Then he cries. " Don't listen to them, my son, you have a beautiful head." his
mother says. " Now, don't cry. Let's go to the shop and buy some apples for you." " But,
Mum, where's the bag? " Peter asks. "I don't have a bag." " Just use your big hat." His
mother says.
请根据短文内容判断正(T)误(F)。
( ) 1. Peter's classmates say Peter has a big head.
( ) 2. Peter's mother thinks Peter has a big head, too.
( ) 3. They want to go to shop for some fruits.
( ) 4. Peter's mother has a big hat.
( ) 5. Peter really has a big head.
如图,两无穷大平行平板的间距为h,中间充满着不可压缩粘性流体,上板(z=h) 相对于下板(z=0) 在自身平面内以不变的速度u=U沿x轴运动,同时流场受到沿x轴的常压力梯度=-G的作用。若流体的粘性系数为μ,求流动达到定常时的速度场和体积流量。