Were there ______ seals at the aquarium? [ ]
A. a lots of
B. some
C. any
D. lot
答案:C
下列何种情况Z成形术宜慎用()
A.松解条索状的直线瘢痕挛缩
B.用于矫正蹼状挛缩
C.用于松解环形狭窄
D.用于错位组织的恢复
E.用于有瘢痕,组织较薄的蹼状挛缩
通过 , 两点的直线绕 轴旋转所得的旋转曲面方程;