题目

The lion is considered a(n) ________ of courage and power, and the other animals see him as kings of the forest.    A. mark                  B. example                   C. sign                  D. symbol 答案：D如图，某地一天从6时至14时的温度变化曲线近似满足函数y=Asin（ωx+∅）+b．（1）求这段时间的最大温差；（2）写出这段时间的函数解析式．