As the crowd rushed towards the gate, several people got______.

A．knocking down

B．knocked off

C．knocking on

D．knocked over

煤工尘肺的晚期主要病理改变是（）

A.煤斑

B.矽结节

C.肺气肿

D.矽性蛋白沉积

E.块状纤维化