从扬声器的发声原理及音箱外形可将音箱分为传统音箱和平板音箱，两者相比，下列关于传统音

题型：单项选择题

问题：

从扬声器的发声原理及音箱外形可将音箱分为传统音箱和平板音箱，两者相比，下列关于传统音箱的说法中不正确的是( )。

A．传统音箱采用活塞式振动方式

B．声音效果与听者位置有很大关系

C．音频效果差

D．振动点只有一个

考点：计算机等级考试PC技术三级PC技术笔试308
题型：单项选择题
阅读理解
                                      Trip 1 One Week In The Mountains
Bring your strong shoes and warm clothes for this walk in a. beautiful area of the Green Mountains. You    may go hiking or have a try of rock climbing. This is also a protection area for wild animals. You can find many kinds of animals living in this area.
Time：May 8-Mayl4      Tel：64639818     Adult：$ 110.00   Child：$ 55.00
                                      Trip 2 Three Days In The Country
There are many beautiful gardens. Take your camera and enjoy the wonderful sight in Hunter Valley. It is a good place for fishing and horse riding. You can also find different kinds of flowers here. This is also a great walk for bird - lovers.
Time：May 20-May 22     Tel= 63986432    Adult：$ 50.00    Child：$ 25.00
                                     Trip3 Flashlight Adventure
Put on your warm clothes，bring a flashlight (手电筒)，and come for a night walk along the Dungog Valley. It is a trip full of adventure (冒险). A guide will lead the tour. Many of the plants you will see on this trip can only be seen at night.
Time：Mayl6-Mayl8     Tel：63875629     Adult：$ 30.00    Not for children
                                   Trip4 Five Days By The Sea
Wear your sun hat and enjoy wonderful sunshine all the time from morning to evening. Our hotel is next to the sea. We have our own boats too. You can swim in the sea or in the swimming pool. Every day our boat will take you to different places for swimming.
Time：May 23-May 27     Tel：67538293   Adult：$ 80.00    Child：$ 40.00
1. What number may you call if you and your friends want to enjoy the sunshine at the seaside?        
A. 67538293.            
B. 63986432.            
C. 64639818
2. Sam wants to stay in Hunter Valley with his wife, his five - year - old daughter and his seven-year - old son.  How much will it cost?      
A. $ 25.            
B. $ 150.            
C. $ 100
3. David loves sports.  He will take his holiday from May 7 to May 15. What activity will he probable take part in?            
A. Hiking in the mountains.
B. Fishing in the country.
C. Watching plants at night
4. Lucy is a college student.  She is quite interested in science. She wants to know something about the life of plants at night. Which trip will she choose?            
A. Trip l.                      
B. Trip 2.                      
C. Trip 3
5. Which of the following is NOT mentioned according to the four advertisements?            
A . Children couldn't take the Trip 3.          
B. We can see some beautiful flowers in Trip 2.            
C. Trip 4 is very dangerous.
查看答案
题型：单项选择题

其盐酸盐加入氢氧化钠后，滴加丙酮，生成黄色结晶的是（）

A.苦参碱

B.麻黄碱

C.伪麻黄碱

D.小檗碱

E.山莨菪碱
查看答案
题型：单项选择题

一患者戴用全口义齿一周，主诉左侧后牙经常咬腮，无其他不适。最可能的原因是（ ）。

A．左侧后牙覆盖过大

B．左侧后牙覆盖过小

C．左侧后牙工作侧干扰

D．左侧后牙平衡侧干扰

E．右侧后牙平衡侧干扰
查看答案
题型：单项选择题

下列史实错误的是（）。

A．战国七雄中，在春秋时期称过霸的是齐、楚、秦

B．以“头悬梁，锥刺股”名闻天下的是张仪

C．寒食节是为了纪念介之推

D．韩信以“明修栈道，暗渡陈仓”之计平定三秦
查看答案
题型：单项选择题

在某工程网络计划中，已知工作M的总时差和自由时差分别为5天和2天，监理工程师检查时发现该工作的实际进度拖后2天，则工作M的实际进度( )。

A．既不影响总工期，也不影响其后续工作的正常进行

B．不影响总工期，但会将其紧后工作的开始时间推迟2天

C．会将其紧后工作的开始时间推迟2天，并使总工期延长2天

D．会将其紧后工作的开始时间推迟4天，并使总工期延长4天
查看答案
更多题库

触屏版 | 网页版 | 题库网

Copyright © m.tikuol.com (粤ICP备2021010849号-1)