皮皮学，免费搜题
登录
搜题
【多选题】
自激振动特点有 ()。A.
自激振荡又称为负阻尼振动,即振动本身运动所产生的阻尼非但不阻止运动,反而将进一步加剧这种运动
B.
自激振动的频率与转子的转速相符
C.
自激振动的频率与其临界转速基本一致
D.
自激振动的振动波形比较紊乱
E.
自激振动的波形含有低频谐波
手机使用
分享
复制链接
新浪微博
分享QQ
微信扫一扫
反馈参考答案：
举一反三
【简答题】生活污水中含有 、病原菌。虫卵等,排入水体或渗入地下水将造成污染,当溶解氧低于 mg/L , 就会影响鱼类的生活。
【简答题】According to the text we can imagine that ________. [A] the doctor was poor too [B] the doctor was skilled and kind [C] the doctor was skilled but cruel D,. the doctor was glad to have got the two boo...
【单选题】You can't prescribe before you ______ as a doctor.
A.
fit
B.
qualify
C.
match
D.
equal
【单选题】---- The doctor told me not to drink too much , but I can’t help myself. ---- The doctor is right . ____ you drink , ______ you will be .
A.
the less ;the healthier
B.
the more ; the healthier
C.
the less; the unhealthier
D.
the more ; the healthiest
【简答题】阅读理解. Old John went to see a doctor . The doctor looked over him and said , 'Medicine can't help you. You must have a good rest. Go to a quiet place for a month , go to bed early , drink some milk , w...
【多选题】下列符合乙醛物理性质的是( )
A.
无色液体，有强烈的刺激臭味，易挥发。
B.
熔点(℃)： -121 沸点(℃)： 20.8
C.
相对密度(水=1)： 0.78
D.
能跟水、乙醇、乙醚、氯仿等互溶
相关题目：
参考解析：
知识点：
题目纠错 0
发布
