A.3.71~3.90
B.3.91~4.10
C.4.11~4.30
D.4.31~4.50
[单选题]A.3.71~3.90B.3.91~4.10C.4.11~4.30D.4.31~4.50
[单选题]A.2100B.2000C.1905D.1900
[单选题]A.2100B.2000C.1905D.1900
[单选题]A.1635B.1650C.1785D.1799
[单选题]A.1.89B.2.66C.3.13D.4.11
[单选题]A.静止B.滑动C.当W很小时能静止D.处于临界状态
[单选题]A.图(a)装置振动周期最大B.图(b)装置振动周期最大C.图(c)装置振动周期最大D.三种装置振动周期相等
[单选题]A.2B.2.5C.3.2D.3.8
[单选题]A.A,B,CB.C,B,AC.C,A,BD.A,C,B