正方形是一个旋转对称图形,它至少旋转______度后,能与自身重合.
正方形可以被其对角线平分成4个全等的部分,则旋转至少360÷4=90度,能够与本身重合.
故答案为:90°
热病后期,产生筋挛肉响、手足蠕动、低热起伏、舌光少津,脉细等,多为
A.肝阳化风
B.热极生风
C.阴虚风动
D.血虚生风
Bill Gates was born ______ October 28, 1955. [ ]
A. on
B. in
C. at
D. of