______ of March is my sister"s birthday.
A. The twenty-one
B. Twenty-one
C. The twenty-first
D. Twenty-first
在上下颌切牙中,牙根圆且直,可以使用旋转力拔牙的牙齿是
A. 上颌侧切牙
B. 下颌侧切牙
C. 上颌中切牙
D. 下颌中切牙
E. 上、下颌中切牙
one, another, other, the other, others, the others I study Chinese, English and some ______ subjects.