The soldier rushed into the cave, his right hand _____ a gun and his face _____ with sweat.

A．held; covered

B．holding; covering

C．holding; covered

D．held; covering

在直角坐标系xOy平面上,平行直线x=n(n=0,1,2,…,5)与平行直线y=n(n=0,1,2,…,5)组成的图形中,矩形共有(   )

A．25个

B．36个

C．100个

D．225个