简述局部流动损失是怎样形成的？

Jim: Let’s play volleyball, OK?

Tony: Sorry, I don’t have a volleyball. But I have a basketball.

Jim: I don’t want to play basketball. I only want to play volleyball.

Tony: Who has a volleyball? Do you know?

Jim: Maybe Tom has one. Let’s go and ask him. （Say to Tom.）

Hi, Tom! Do you have a volleyball?

Tom: No. I don’t. Does Peter have one?

Tony: Oh, yes, he does.

Tom: Hi, Peter! Do you have a volleyball?

Peter: Yes, I do. But it is at home.

Tom: Sorry to hear that!

Tony: Well, let’s play basketball. OK?

Jim: OK!

Tom: Peter, please join us.

Peter: OK! Let’s play!

根据对话内容，选择每个问题的正确答案。

小题1:Who wants to play volleyball?

A．Jim.

B．Tony.

C．Peter.

D．Tom.小题2:Does Tony have a basketball?

A．Yes, he does.

B．No. he doesn’t.

C．Yes, he is.

D．No, he isn’t.小题3:Who has a volleyball?

A．Jim.

B．Tony.

C．Peter.

D．Tom.小题4:Where is Peter’s volleyball?  

A．On the bed.

B．At school.

C．Under the desk.

D．At home.小题5:Can they play volleyball？

A．Yes,they can.

B．No,they can’t

C． Yes,they do

D．No,they don’t

下列各组词语中，没有错别字的一组是         

A．布署文绉绉哄堂大笑一切就绪

B．倾注热烘烘顶礼膜拜事得其反

C．相像座右铭无可辩驳慢条斯理

D．凋蔽度假村悬梁刺骨震撼人心

选修4-4：坐标系与参数方程

在直角坐标系xOy中，直线l经过点P（-1，0），其倾斜角为α，以原点O为极点，以x轴非负半轴为极轴，与直角坐标系xOy取相同的长度单位，建立极坐标系．设曲线C的极坐标方程为ρ²-6ρcosθ+5=0．

（1）若直线l与曲线C有公共点，求α的取值范围；

（2）设M（x，y）为曲线C上任意一点，求x+y的取值范围．

The injured person was still ________ on the bed where he was ________.[ ]

A. lying; lay  

B. lied; laying

C. lying; laid  

D. lain; lying

在数据流图(DFD) 中，带有名字的箭头表示______。

A．控制程序的执行顺序

B．模块之间的调用关系

C．数据的流向

D．程序的组成成分