采用不同的基色荧光粉和不同的(),将有不同的亮度方程。A、白光源 B、比例 C、检波

题型:单项选择题

问题:

采用不同的基色荧光粉和不同的(),将有不同的亮度方程。

A、白光源

B、比例

C、检波

D、编码

考点:电子与通信技术电视机原理电视机原理题库
题型:单项选择题

Now satellites(卫星)are helping to forecast(预报)the weather. They are in space and they can reach any part of the world.The satellites take pictures of the atmosphere(大气), because this is where the weather forms(形成)。They send these pictures to the weather station. So meteorologists(气象专家)can see the weather of any part of the world. From the pictures, the scientists can often say how the weather will change.

Today, nearly five hundred weather stations in sixty countries receive satellite pictures. When they receive new pictures,the meteor- ologists compare(比较)them with earlier ones. Peerhaps they may find that the clouds have changed during the last few hours .This may mean the weather on the ground may soon change,too. In their next weather forecast, the meteorologists can say this.

So the weather satellites are a great help to the meteorologists. Before satellites were invented, the scientists could forecast the weather for about 24 or 48 hours. Now they can make good forecasts for 3 or 5 days. Soon,perhaps , they may be ablet to forecast the weather for a week or more ahead(提前)

小题1:Satellites travel__________.

A in space           B in the atmosphere

C above the ground    D above space

小题2:Why do we use the weather satellites to take pictures of the atmosphere? Because___________.

A the weather satellites can do it easily

B clouds form there

C the weather forms there

D the pictures can forecast the weather

小题3: Meteorologists forecast the weather________.

A when they have received satellite pictures

B after they have compared new satellite pictures with earlier ones

C before they receive satellite pictures

D while they study satellite pictures

小题4:Maybe we’ll soon be able to forecast the weather for _______.

A one day   B two days  C five days   D seven days or even longer

小题5:The main idea of this passage is that satellite are now used    in______.

A taking pictures of the atmosphere

B receiving pictures of the atmosphere

C doing other work in many ways

D weather forecasting

题型:单项选择题

While staying in Scotland alone, _____. [ ]

A. loneliness was always around me

B. many interesting places were visited

C. I was a bit homesick

D. my friends in China encouraged me a lot

题型:单项选择题

今晨突感下腹疼痛加剧,经检查诊断输卵管妊娠破裂,以下处理哪项正确

A.口服止血药物

B.继续观察

C.手术治疗

D.输血

E.静脉滴注抗生素

题型:单项选择题

《智能变电站继电保护技术规范》规定,继电保护装置应满足()要求

A.线路纵联保护、母线差动保护、变压器差动保护应适应常规互感器和电子式互感器混合使用的情况。

B.保护装置应自动补偿MU的采样响应延迟,当响应延迟时发生变化时应闭锁采自不同MU且有采样同步要求的保护。

C.保护装置的采样输入接口数据的采样频率宜为4000Hz。

D.保护装置的采样输入接口数据的采样频率宜为8000Hz。

E.保护装置的交流电流、交流电压及保护设备参数的显示、打印、整定应能支持一次值,上送信息应采用一次值。

题型:单项选择题

冷风渗透耗热量计算的常用方法有哪些?

更多题库