题目内容

1000 years ago, Chinese invented paper-making.

A. 对
B. 错

查看答案

搜索结果不匹配？点我反馈

更多问题

Writing brushes, Chinese inks, rice paper and ink slabs are the basic tools of calligraphy.

A. 对
B. 错

The body of gu qin is made of wood and the strings are made of silk.

A. 对
B. 错

RC正弦波振荡器的振荡频率取决于什么?

频率调节范围为20~200Hz的RC正弦波振荡器，电容C = 0.27μF，如果用双联可变电阻来调节振荡频率，求可变电阻器的电阻值的变化范围。