电压互感器文字符号用()标志。A、PA B、PV C、TA D、TV

题型:单项选择题

问题:

电压互感器文字符号用()标志。

A、PA

B、PV

C、TA

D、TV

考点:电能计量检定考试电能计量检定考试题库
题型:单项选择题

一个正方体的棱长之和是12厘米.体积是1立方厘米.______.

题型:单项选择题

卵黄的作用是(  )

A.提供胚胎初期发育所需的营养

B.提供卵细胞成熟所需的营养

C.保护卵细胞

D.支持卵细胞

题型:单项选择题

     Pocket Tape-Recorders"Family and Home Magazine" test what's on the market now.

     1)Pearlcorder S702 $64

     This simple model at the bottom of the Olympus range scored the most points for its excellent quality

of recording. Background noise hardly affects the sound and recording from a pocket is perfectly possible, but it doesn't turn off automatically.

     Tape length: 30 minutes per side. Weight:240g.

     2)Sony M9 $49.95

    Small and very good looking, sony's latest offering scored most for appearance. Sounds clear, but

there is slight machine noise. The big control buttons are a great improvement on some of the complicated

little controls on other tape-recorders. Doesn't switch off automatically but a red light shows if the machine is still running.

    Tape length: 60 minutes per side. Weight: 195g.

3)Sony M400 $115

     Lots of little control buttons that make a noise and are difficult to use . Recording was good but

machine noise lost points. Tape counter and automatic switch-off when tape has finished recording or

rewinding are useful Tape length: 60 minutes per side. Weight: 230g.

4)Imperial OEM. MC $29.95

     Cheap and simple compared with the rest, but recording was good as long as there was no

background noise. Use only its own make of cassette. No light to show it is on; no fast forward button

and the record button makes a loud noise.

      Tape length: 30 minutes per side. Weight: 285g.

5)Philips 585 $80

     Handsome and simple to use, but recording is very poor at more than the recommended distance of

5 cm-designed for dictation. No recording light. Tape length: 15 minutes per side. Weight: 220g.

1. The machine that produces the best recording with the least unwanted noise is the             .

A. Pearlcorder S702  

B. Sony M9    

C. Sony M400

D. Imperial OEM MC7

2. It you want a machine which turns off automatically and weighs very little you should choose the           .

A. Pearlcorder S702    

B. Sony M9    

C. Sony M400

D. Philips 585

3. Which machine is unsuitable for general use?

A. Pearlcorder S702

B. Imperial OEM MC7

C. Sony M400

D. Philips 585

4. What disadvantage does only the Imperial OEM MC7 have?

A. No light shows when it is on

B. It requires a special cassette.

C. It picks up background noise.

D. The record button makes a noise.

题型:单项选择题

全球气压带、风带的形成,主要受到影响因素有()

①地转偏向力

②地表受热不均

③气压分布状况

④海陆分布不均

A.①②

B.②③

C.③④

D.①④

题型:单项选择题

博来霉素最严重的不良反应是( )。

A.骨髓抑制
B.脱发
C.肺纤维化
D.胃肠道反应
E.心脏毒性

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