皮皮学,免费搜题
登录
搜题
【单选题】
Part Ⅱ Reading Comprehension (Skimming and Scanning) Directions: In this part, you will have 15 minutes to go over the passage quickly and answer the questions on Answer Sheet 1. For questions 1-7, choose the best answer from the four choices marked A), B), C) and D). For questions 8-10, complete the sentences with the information given in the passage. Satellite Ⅳ Today, you see compact satellite dishes perched on rooftops all over the United States. Drive through rural areas beyond the reach of the cable companies and you'll find dishes on just about every house. The major satellite television companies are bringing in more customers every day with the lure of movies, sporting events and news from around the world. The Broadcast TV Problem Conceptually, satellite television is, a lot like broadcast television. It's a wireless system for delivering television programming directly to a viewer's house. Both broadcast television and satellite stations transmit programming via a radio signal. Broadcast stations use a powerful antenna to transmit radio waves to the surrounding area. Viewers can pick up the signal with a much smaller antenna. The main limitation of broadcast television is range. The radio signals used to broadcast television shoot out from the broadcast antenna in a straight line. In order to receive these signals, you have to be in the direct 'line of sight' of the antenna. One problem is that the Earth is curved, so it eventually breaks the signal's line of site. The other problem with broadcast television is that the signal is often distorted even in the viewing area. To get a perfectly clear signal like you find on cable, you have to be pretty close to the broadcast antenna without too many obstacles in the way. The Satellite TV Solution Satellite television solves the problems of range and distortion by transmitting broadcast signals from satellites orbiting the Earth. Since satellites are high in the sky, there are a lot more customers in the line of site. Satellite television systems transmit and receive radio signals using specialized antennas called satellite dishes. The television satellites are all in geosynchronous orbit, meaning that they stay in one place in the sky relative to the Earth. Each satellite is launched into space at about 7,000 mph (11,000kph), reaching approximately 22,200 miles (35,700km) above the Earth. At this speed and altitude, the satellite will revolve around the planet once every 24 hours—the same period of time it takes the Earth to make one full rotation. In other words, the satellite keeps pace with our moving planet exactly. This way, you only have to direct the dish at the satellite once, and from then on it picks up the signal without adjustment, at least when everything works right. The Overall System Early satellite TV viewers were explorers of sorts. They used their expensive dishes to discover unique programming that wasn't necessarily intended for mass audiences. The dish and receiving equipment gave viewers the tools to pick up foreign stations, live feeding between different broadcast stations, NASA activities and a lot of other stuff transmitted using satellites. Some satellite owners still seek out this sort of programming on their own, but today, most satellite TV customers get their programming through a direct broadcast satellite (DBS) provider, such as Direct TV or the Dish Network. The provider selects programs and broadcasts them to subscribers as a set package. Basically, the provider's goal is to bring dozens or even hundreds of channels to your television in a form. that approximates the competition, cable TV. Unlike earlier programming, the provider's broadcast is completely digital, whic
A.
a powerful antenna
B.
a much smaller antenna
C.
satellite dishes
D.
cable
拍照语音搜题,微信中搜索"皮皮学"使用
参考答案:
参考解析:
知识点:
.
..
皮皮学刷刷变学霸
举一反三
【单选题】双黄连口服液应进行
A.
内毒素检查
B.
效价检测
C.
无菌检测
D.
微生物限度检查
E.
微生物总数检测
【多选题】下列关于道德本质的说法中正确的时是
A.
道德是反映社会经济关系的特殊意识形态
B.
道德是社会利益关系的特殊调节方式
C.
道德是一种制度化的、刚性的规范
D.
道德是一种实践精神
【单选题】斜切面韧皮部有树脂状分泌物呈红棕色至黑棕色,与木质部相间排列呈3~8个偏心性半圆形环的药材是
A.
木通
B.
钩藤
C.
大血藤
D.
鸡血藤
E.
桑枝
【判断题】C:\a>cd d 进入C盘下文件夹d
A.
正确
B.
错误
【单选题】用MD命令在D盘下新建一个名为BB的文件夹,再用CD命令进入到BB 这个文件夹,然后用MD再新建一个名为CC的文件夹,现在想册除BB文件夹,用的命令是
A.
RD BB
B.
RD CC
C.
RD  BB  /Q
D.
RD  BB /S /Q
【单选题】关于道德品质的说法正确的是()
A.
一个人道德品质的好坏由他对道德的认识所决定
B.
如果一个人做了一件好事就说明他是有道德的
C.
“人之初,性本善”
D.
道德品质是在道德行为的基础上形成的
【多选题】双选:以下关于道德的本质的说法正确的是()
A.
道德不具有阶级性
B.
道德的产生,发展和变化源于社会经济关系
C.
在人类道德史上,并不是所有道德的兴衰起伏,进退消长都源于社会经济关系的变革
D.
道德是社会利益关系的特殊调节方式
【单选题】横切面可见韧皮部有红棕色或黑棕色树脂状分泌物,木部红棕色,有多数导管小孔,韧皮部与木质部相间排列呈3~8个偏心性半圆形的环。此药材是( )
A.
川木通
B.
鸡血藤
C.
沉香
D.
降香
E.
大血藤
【单选题】韧皮部与木质部相间排列呈3~8个偏心性半圆形环的中药材是
A.
木通
B.
钩藤
C.
苏木
D.
大血藤
E.
鸡血藤
【多选题】下列关于道德本质的说法,正确的是()
A.
道德决定了经济基础和社会关系
B.
道德是反映社会经济关系的特殊意识形态
C.
道德是社会利益关系的特殊调节方式
D.
道德是一种实践精神
相关题目: