综合填空（每小题1分，共10分）
Long, long ago there was a bad king. All of his people h 小题1: him.
One hot day he was taking a walk along a river when he decided to have a swim in it. He was a good s 小题2: . But while he was in the river, he s 小题3:fell ill, and was nearly drowned(淹死). At that time two f 小题4:were working in the field n 小题5:They came over, jumped into the river, and he was s 小题6: . They didn’t know who he was until they p 小题7: him out of the water.
The king was happy. He said to the two farmers, “Ask for a 小题8: , I’ll give it to you. I’m the r 小题9: in the world. And today you have saved my life.”
One of them answered, “You can do one thing for us.” “What is it?” asked the king. He thought that they would ask for a lot of money.
“Don’t tell a 小题10: that we have saved you.”
的波形如图，则此元件是（）。
