我们将使用低阶的波形声音API（即，前缀是waveOut的函数）来建立一个称作SINEWAVE的声音正弦波生成器。此程序以1 Hz的增量来生成从20Hz（人可感觉的最低值）到5,000Hz（与人感觉的最高值相差两个八度音阶）的正弦波。-We re going to use the low-level waveform audio APIs (that is, the functions beginning with the prefix waveOut) to create an audio sine wave generator called SINEWAVE.