问题
填空题
确定性信号分为（）.
答案
参考答案：周期信号和非周期信号
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确定性信号分为（）.
参考答案：周期信号和非周期信号
| 完形填空。 | ||||
| We see many animals, like rabbits, bees, dogs, birds, sheep but do you know 1 these animals say things? First, let's see a rabbit. When a rabbit sees something 2 , it runs away at once. When it runs, its tail moves up and 3 . When others see this, they run 4 . Many other animals use this kind of 5 . When a bee finds some food, it goes back to its home. It cannot tell 6 bees where the food is by speaking 7 them, but it does a little dance in the air. This may tell other bees 8 the food is. Some animals say things by making sounds (声音) like a man 9 . A dog barks when a stranger (陌生人) comes near. Some birds can make several (几种) 10 sounds, each with its own meaning. In a word, every animal has its own language. | ||||
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