[单项选择]

People around the globe hit the height of their misery and depression in (51) age, a new international study suggests.
The finding by British and American researchers was based on an analysis of well-being among approximately 2 million people in 80 nations. With few exceptions, the observation appears to apply across the board, regardless {{U}}(52) {{/U}} gender, culture, geography, wealth, job history, education, and marriage or parental status.
"The scientific fact seems to be that happiness and positive mental health follow a giant ’U’ (53)  through life, " said study author Andrew J. Oswald, a professor of economics at Warwick University in Warwickshire, England. "For the average person, it’s high when you’re 20, and then it slowly falls and bottoms out (54)  your 40s. But the good news is that your (55)  health picks up again, and eventually gets back to the high levels o
A. curve
B. line
C. axis
D. table

People around the globe hit the height of their misery and depression in (51) age, a new international study suggests.
The finding by British and American researchers was based on an analysis of well-being among approximately 2 million people in 80 nations. With few exceptions, the observation appears to apply across the board, regardless {{U}}(52) {{/U}} gender, culture, geography, wealth, job history, education, and marriage or parental status.
"The scientific fact seems to be that happiness and positive mental health follow a giant ’U’ (53)  through life, " said study author Andrew J. Oswald, a professor of economics at Warwick University in Warwickshire, England. "For the average person, it’s high when you’re 20, and then it slowly falls and bottoms out (54)  your 40s. But the good news is that your (55)  health picks up again, and eventually gets back to the high levels o
A. old
B. middle
C. right
D. young

Telecommunications allows people around the World to contact one another, to access information instantly, and to communicate from remote areas. Telecommunications usually involves a sender of information and one or more recipients(收件人) linked by a technology, such as a telephone system, that transmits information from one place to another. Telecommunications devices convert different types of information, such as sound and video, into electronic signals. The signals can then be transmitted by means of media such as telephone wires or radio waves. When a signal reaches its destination, the device on the receiving end converts the electronic signal back into an understandable message, such as sound over a telephone, moving images on a television, or words and pictures on a computer screen. Telecommunications enables people to send and receive personal messages across town, between countries, and to and from outer space. It also provides the key medium for news, data, information&r
A. Telecommunications are devices and systems that transmit electronic signals across long distances.
B. Telecommunications allows people around the world to contact one another, to access information instantly, and to communicate from remote areas.
C. Telecommunications usually involves a sender of information and one or more recipients(收件人) linked by a technology.
D. Telecommunications are devices and systems that carry, electronic signals across short distances.