工程项目目标具有（）的特点。 A.一次性、多目标性、优先性 B.唯一性、多目标性、层

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The first MP4 player was born years ago. Soon many music fans were wondering how fantastic it is! If you have been into technology enough, perhaps you may have a knowledge of the MP4. If not, you do need to know something before buying one, even if you are familiar with MP3. MP3 is the CD-like disc with greater capacity. How about MP4? This small digital product will really enrich the joy from listening to music. You can even feel the “touch” of music to your soul!

Now, some similar digital products advertised as “MP4 players” are simply MP3 players, which do not play video and MPEG format (格式) and also lack other particular functions. These products confuse some buyers, as they may think the “MP4” players simply mean they can do more than MP3.

What is MP4?!

It is a multimedia container. It is not only used to store digital audio (音频) and digital video streams, especially those of MPEG, but can also be used to store other data such as subtitles (字幕) and pictures. As a most modern container format, it allows streaming over the Internet.

With the help of a piece of MP4 video equipment, you can change various programs such as MPEG to MP4, ASX to MP4, AVI to MP4 and so on, which can be done very quickly and easily without any effect on the sound quality. By installing (安装) DVD-MP4 software, you can transfer particular music from a DVD to an MP4 video file. It really excites your listening music experience. 

Then, there is MP4 advanced and you can set your own collection of all the programs — TV shows, games, and music. You can even see movies which are still running in cinemas. What else digital product could you possibly ask for? 

57. It is suggested here that you should ________ before buying an MP4 player

A. first be a music fan                                 B. have a knowledge of MP4

C. get familiar with MP3                                  D. buy a CD-like disc

58. From the passage, we can see that MP4 is ________ MP3. 

A. much bigger than              B. just as advanced as  

C. not so particular as              D. more functional than

59. Which function of MP4 is NOT directly mentioned in this passage?

A. Storing digital audio and video streams.    B. Recording some movies in cinemas.

C. Playing TV shows, games and movies.      D. Transferring particular music from a DVD.

60. From the last sentence, it’s clear that the writer tries to tell us it is _______.

A. reasonable to buy other digital products    B. impossible to buy something else

C. a very wise choice to buy an MP4       D. an exciting experience to buy an MP3  

男性，15岁。皮肤广泛紫癜伴大量鼻出血一周，病前两周有上呼吸道感染史。肝、脾不大。血红蛋白80g/L，白细胞9.4×10⁹/L，血小板10×10⁹/L。出血时间9min，束臂试验阳性。骨髓有核细胞增生活跃，粒细胞系统和红细胞系统正常，巨核细胞增多，以幼巨核细胞为主，未见产血小板型巨核细胞。最可能的诊断是（）

A.急性白血病

B.再生障碍性贫血

C.巨幼细胞贫血

D.慢性型特发性血小板减少性紫癜

E.急性型特发性血小板减少性紫癜

男婴12d，足月顺产。生后第3天出现黄疸，近2d食欲减退，黄疸加重。体检：脐部红肿，有脓性分泌物，肛门温度35．5℃。

本病易发生的并发症是（）

A.肝脓疡

B.肺脓疡

C.脑膜炎

D.腹膜炎

E.骨髓炎

针对不同的保护目的，接地可分为防雷接地、工作接地和保护接地。

简述土地的特征。