如图所示,位于介质I和II分界面上的波源S,产生两列分别沿x轴负方向与正方向传播

题型:选择题

问题:

如图所示,位于介质I和II分界面上的波源S,产生两列分别沿x轴负方向与正方向传播的机械波.若在两种介质中波的频率及传播速度分别为f1、f2和v1、v2,则(  )

A.f1=2f2,v1=v2

B.f1=f2,v1=0.5v2

C.f1=f2,v1=2v2

D.f1=0.5f2,v1=v2

考点:横波与纵波波长、频率和波速
题型:选择题

One of sweetest memories as a child is of going down to the river and sitting comfortably on the bank. There I would enjoy the peace and quiet, watch the water rush downstream and listen to songs of birds. I would also watch the bamboo trees bend under the pressure from the wind and watch them return gracefully to their original state after the wind had died down.

When I think about the bamboo tree’s ability to bend and move back, the word “resilience” comes to my mind. When it is used for a person, this word means the ability to readily recover(恢复) from shock, sadness or any other suffering. Have you ever felt like you were going to snap? Have you ever felt like you were at your breaking point? Thankfully, you have survived to talk about it.

Life is a mixture(混合) of good times and bad times, happy moments and unhappy moments. The next time you are experiencing one of those bad times or unhappy moments that take you close to your breaking point, bend, but don’t break. Try your best not to let the situation get the best of you.

An amount of hope will take you through the unpleasant suffering. With hope for a better tomorrow or a better situation, things may not be as bad as they seem. The unpleasant suffering may be easier to deal with if the end result is worth having.

If things get tough and you are at your breaking point, show resilience. Like the bamboo trees, bend, but don’t break!

小题1:What does the word “snap” in the second paragraph most probably mean?

A.break

B.change

C.win

D.Complain小题2:What can help people get through sufferings according to the writer?

A.Holding peace and quiet in mind.

B.Waiting until sufferings disappear.

C.Experiencing more bad times.

D.Hoping for a better tomorrow.小题3:What would be the best title of this passage?

A.Memories of Bamboo

B.Be Like Bamboo

C.Enjoying Bamboo

D.Characteristics of Bamboo

题型:选择题

根据税法的基础内容,下列说法不正确的是( )。

A.税收基本法是税法体系的主体和核心

B.个人所得税法属于税收实体法

C.税收征收管理法属于税收普通法

D.国际税法就是外国各个国家制定的税法

题型:选择题

在wood中,关于合并字符的描述正确的是()

A.合并字符功能可以将多个字符合并为一个(最多可以合并6个字符)

B.要合并字符可以在“格式”菜单中选择“中文版式”子菜单下“合并字符”命令,屏幕将弹出“合并字符”对话框

C.可以在“文字”框中输入要合并的字符,并设定字体和字号

D.在预览框中可以看到合并后的效果

题型:选择题

有人发起“多吃素食、少吃肉食”的运动,以支援粮食短缺地区的灾民。运用生态学知识对此的合理解释是( )。

A.多吃肉食会增加心血管病的发病率
B.直接以低营养级的生物为食将消耗生态系统更多的能量
C.多吃肉食比多吃素食消耗的粮食总量更多
D.节省的肉食可以帮助灾民提高营养水平

题型:选择题

下面是关于PC机中CPU的I/O地址空间的叙述,其中错误的是______。

A.PC机中CPU的I/O地址空间由64K个可独立编址的8位端口(即64K字节)组成

B.PC机中CPU的I/O地址空间是实际的物理空间,不经过分段和分页硬件处理

C.PC机主板和芯片组器件通常使用从00H到FFH的I/O端口地址

D.PC机中CPU的I/O指令采用直接寻址方式时,I/O端口的寻址范围为0000H至 FFFFH

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