直流电机电刷在刷盒下端的露出高度,即刷盒离换向片表面的距离应保持一致,应在( )。
A.1~2mm
B.2~3mm
C.2~4mm
D.3~4mm
参考答案:C
My mother was _______ me because I didn't finish my homework. [ ]
A. interested in
B. mad about
C. excited at
D. angry with
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