乡镇武装部长使用县委“安发干”文件向（）提名任免，由武装部行文。
参考答案：武装部党委
At the party, as well as ________, a shy girl, one of my classmates performed two wonderful dances. [ ]
A. sang
B. singing
C. sing
D. to sing
简述回转波的特点？
