By using the sign-and-magnitude coding scheme, the binary sequence 1101.01 represents a decimal number with its value equal to

133 Using the WBS shown in the Special window, a typical work package would be:

A. Software development

B. Systems design

C. Coding

D. A, B, and C

E. None of the above

All of the following statements are supported by the passage EXCEPT______

A．True bacteria form. a distinct evolutionary group.

B．Archaebacteria are prokaryotes that resemble true bacteria.

C．True bacteria and eukaryotes employ similar types of genetic coding.

D．True bacteria and eukaryotes are distinguishable at the subcellular level.

E．Amino acid sequences of enzymes are uniform. for eukaryotic and prokaryotic organisms.

Digital data can also be represented by (71)signals by use ofa modem. The modem converts a series of binary voltage (72) into an analog signal by encoding the digital data ontoa carrier frequency. The resulting signal occupies a certam spectrum of (73) centered about the carTier and may be propagated acrossa medium suitable for that carrier. The most common modems represent digital data in the voice(74)and hence allow those datato be propagated over ordinary voice-grade (75 )lines At the other end of the line, another modem demodulates the signal to recover the original data

(71)

A.analog

B.digital

C.Modem

D.electric

《商品名称和编码协调制度》(the harmonized commodity description and coding system)，简称《协调制度》，英文简称(  )。

  A．H.  B．H.S  C．H.C  D．C.D

Scientists have long been interested in how the deaf process signed languages in the braia Understanding that activity could shed light to whether the brain contains specialized structures for decoding【M1】______ linguistic patterns in general regardless how they are conveyed. A【M2】______ new study published in Tuesdays issue of Proceedings of the National Academy of Science suggests that the brain does have such wiring, challenged the idea that speech and sound are vital for human【M3】______ language. Laura Ann Petitto and other researchers base their conclusions on a series of experiments which involves 11 profoundly deaf people and 10 hearing people. Earlier work had demonstrated that deaf people were processing signed sentences used mostly their left【M4】______ hemispheres, just as hearing people parsing spoken language. But the【M5】______ new study found that in addition, both groups rely on identical brain structures for similar tasks. The researchers were particularly stunned by this activity in the brain of the deaf. The puzzled finding has led Petitto and Zatorre to propose that【M6】______ perhaps areas of the brain once viewing as devoted to sounds actually【M7】______ contain different types of cells that are capable of responding at the【M8】______ patterns of natural language in any form. "Such neural specialization for aspects of language patterning appears to be neurally modifiable,【M9】______ as languages with radically different sensory modalities such as speech and sign are processed at different brain sites", the authors write,【M10】______ "while, at the same time, the neural pathways for expressing and perceiving natural language appear to be neurally highly modifiable."

【M1】

A、dynamic mutation

B、frame shift mutation

C、point mutation

D、nonsense mutation

There are three basic sections which make up a receiver: the tuner or radio signal receiving section, the preamplifier control section, and the power amplifier section. In very elaborate hi fi systems these three sections actually may be purchased as separate units, for increased flexibility and control or as a means of assembling the system in stages using the "building block" approach.

The Tuner Section

The tuner section may be equipped to receive only FM signals or both AM and FM signals. Since it is possible to broadcast stereo (two channel) sound via FM, most hi fi receivers have circuitry for decoding the complex composite received signal into separate "left and right" channel signals.

The front end of the tuner section selects the particular signal desired from the hundreds of radio signals present in the atmosphere. As you tune the dial, resonant or tuned circuits are changed so as to be responsive to a single frequency. In the case of FM signals, tuning is adjustable from 88 MHz (millions of alternations/second of the radio wave) to 108 MHz. Since each FM station occupies a space of 0.2 MHz, that means a theoretical maximum of 100 stations is possible in one geographical area. Actually fewer stations are assigned in any one area, so that one station' s signal will not cause audible interference with an adjacent station. In the case of AM, stations broadcast at frequencies ranging from 540 kHz to 1605 kHz (1 kHz = 1000 alternations per second) and selection of desired stations is similar to the technique used in FM.

The signal is amplified by the front end and mixed with a locally generated signal in the receiver to produce a different frequency known as the IF signal (Intermediate Frequency). In the case of AM, the IF frequency is generally 455 kHz. In the case of FM radio, the IF frequency is 10.7 MHz. The process is known as super heterodyne and since the local signal and received signal are always a fixed amount apart, the succeeding IF amplifiers need not be variably tuned but can be designed simply to amplify 455 kHz (for AM) or 10.7 MHz (for FM).

Difference Between FM and AM

In AM radio the amplitude of the radio wave is varied in accordance with the audio information to be broadcast. Hence the name Amplitude Modulation. In FM it is the radio frequency that is varied based on audio signals. It is this feature that makes FM relatively noise free since noise or static is an amplitude phenomenon. If noise accompanies the FM signals the noise can be sliced off by circuits called limiters without impairing the frequency-changing nature of the FM signal.

While the circuits themselves differ, the amplified IF signals are then applied to a detector circuit which strips off the original audio information. In FM, the detector is called a radio detector. The output of either the AM detector or the FM detector is an audio signal suitable for application to and further processing by the "preamplifier control" section o{ the receiver.

In the case o{ stereo FM the recovered audio signal must be further processed or "unscrambled" to recover the separate "left" and "right" audio channels. This is accomplished by the multiplex decoder circuits.

In an FM radio, the Intermediate Frequency is usually ______.

A．10.7 MHz

B．455 kHz

C．540 kHz

D．1605 kHz

It’s true that high-school coding classes aren’t essential for learning computer science in college. Students without experience can catch up after a few introductory courses, said Tom Cortina, the assistant dean at Carnegie Mellon’s School of Computer Science.

However, Cortina said, early exposure is beneficial. When younger kids learn computer science, they learn that it’s not just a confusing, endless string of letters and numbers — but a tool to build apps, or create artwork, or test hypotheses. It’s not as hard for them to transform. their thought processes as it is for older students. Breaking down problems into bite-sized chunks and using code to solve them becomes normal. Giving more children this training could increase the number of people interested in the field and help fill the jobs gap, Cortina said. Students also benefit from learning something about coding before they get to college, where introductory computer-science classes are packed to the brim, which can drive the less-experienced or-determined students away.

The Flatiron School, where people pay to learn programming, started as one of the many coding bootcamps that’s become popular for adults looking for a career change. The high-schoolers get the same curriculum, but “we try to gear lessons toward things they’re interested in,” said Victoria Friedman, an instructor. For instance, one of the apps the students are developing suggests movies based on your mood.

The students in the Flatiron class probably won’t drop out of high school and build the next Facebook. Programming languages have a quick turnover, so the “Ruby on Rails” language they learned may not even be relevant by the time they enter the job market. But the skills they learn — how to think logically through a problem and organize the results — apply to any coding language, said Deborah Seehorn, an education consultant for the state of North Carolina.

Indeed, the Flatiron students might not go into IT at all. But creating a future army of coders is not the sole purpose of the classes. These kids are going to be surrounded by computers — in their pockets, in their offices, in their homes — for the rest of their lives. The younger they learn how computers think, how to coax the machine into producing what they want — the earlier they learn that they have the power to do that — the better.

Cortina holds that early exposure to computer science makes it easier to____.

A.complete future job training

B.remodel the way of thinking

C.formulate logical hypotheses

D.perfect artwork production

In delivering lessons for high-schoolers, Flatiron has considered their____.A.experience

B.academic backgrounds

C.career prospects

D.interest

The word “coax” (Line4, Para.6) is closest in meaning to____.A.challenge

B.persuade

C.frighten

D.misguide

Deborah Seehorn believes that the skills learned at Flatiron will____.A.help students learn other computer languages B. have to be upgraded when new technologies come

B.need improving when students look for jobs

C.enable students to make big quick money

According to the last paragraph, Flatiron students are expected to____.A.compete with a future army of programmers

B.stay longer in the information technology industry

C.become better prepared for the digitalized world

D.bring forth innovative computer technologies

请帮忙给出每个问题的正确答案和分析，谢谢！