【单选题】当二阶系统的阻尼比【图片】在0<【图片】
【单选题】当二阶系统的根分布在根平面的虚轴上时,系统的阻尼比为( )
【单选题】Nowadays teens prefer going to the cybercafé ,_____ ,as is known to us, they can chat with their friends by QQ or play games.
【单选题】What does the story intend to tell us?
A.
Little people can make a big difference
B.
A friend in need is a friend indeed
C.
East or West,home is best