一个非正弦周期波可分解为无限多项（）成分，这个分解的过程称为（）分析，其数学基础是（）。
参考答案：谐波；谐波；傅里叶级数
正常的横扫球击球时，位于板柄（）手发力，紧握球板。
SWOT analysis is a kind of risk identification method. If the project team chose the SO strategy, they should（）.
A.make full use of the advantage and catch the opportunity
B.overcome the weakness and catch the opportunity
C.make full use of the advantage and reduce the threat
D.overcome the weakness and reduce the threat
