流浸膏剂的制备多用()。
A.浸渍法
B.回流法
C.渗漉法
D.煎煮
参考答案:C
— Mr. Smith never means what he says. I dislike him.
— , as the saying goes.
A.A single flower does not make a spring
B.A still tongue makes a wise head
C.A man of words and not of deeds is like a garden full of weeds
D.Actions speak louder than words
木块A、B分别得50 N和30 N,它们与水平地面之间的动摩擦因数均为0.2.与A、B相连接的轻弹簧被压缩了5 cm,系统置于水平地面上静止不动.已知弹簧的劲度系数为100 N/m.用F=1 N的不变力作用在木块A上,如图所示.力F作用后( )
A.木块A所受摩擦力大小是4 N,方向向右
B.木块A所受摩擦力大小是9 N,方向向右
C.木块B所受摩擦力大小是9 N,方向向左
D.木块B所受摩擦力大小是6 N,方向向左