旋风除尘器的原理是利用气流旋转过程中作用在尘粒上的(),使粉尘从含尘气流中分离出来。
A、弹力
B、电磁力
C、离心力
参考答案:C
While Mark Twain seemed to have paid more attention to the “life” of the Americans, ________ had apparently laid a greater emphasis on the “inner world” of man.
A.William Howells
B.Henry James
C.Bret Harte
D.Hamlin Garland
杭州市在职职工医疗互助包括几种重大疾病()。
A、25
B、28
C、30
D、40