治疗小儿肺炎喘嗽风寒闭肺证的首选方剂是( )
A．华盖散B．麻黄汤C．荆防败毒散D．杏苏散E．小青龙汤
参考答案：A
Joanna is no less hardworking than her twin sister, _______ she failed in the final exam.
A．but
B．so
C．or
D．and
如图所示,水平力F=100 N,木块的重量为40 N沿着竖直墙壁匀速下滑,则木块与墙壁间的动摩擦因数为μ=________;若水平力增大到200 N,木块受到的摩擦力f1=________ N;若水平力减小到80 N,木块受到的摩擦力f2=________ N.
