A:80°
B:70°
C:65°
D:60°
如图所示是一手压电筒,按压手柄,塑料齿轮带动线圈内磁性飞轮高速旋转,使灯泡发光.下列四图中与这一过程的工作原理相同的是( )
血浆具有的功能是( )
The boy has made rapid progress, and he has already ______ in ______ the exam.