The word peak in paragraph 2 is closest in meaning to
A. large vocabulary
B. difficult period
C. high point
D. sudden reversal
查看答案
The term waterlogging in paragraph 6 means that
A. logs are floating in water
B. water is not available
C. the soil holds too much water
D. salts are removed from water
Which of the following statements can be inferred from paragraph 1 about the history of communication？
A. Certain advances in technology have greatly changed communication．
B. People have both loved and feared new developments in technology．
C. We do not know what people thought about before modern technology．
D. The history of modern communication began in the fifteenth century．
The word each in paragraph 4 refers to
A. experiment
B. child
C. age
D. row
How are waterlogging and salinization related？
A. Salinization occurs only where waterlogging is a problem．
B. Waterlogging raises and concentrates salts near the surface．
C. Farmers add salts to irrigation water as a way to fertilize soil．
D. Both waterlogging and salinization contribute to soil erosion．
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