皮下出血
参考答案：致伤物作用于皮肤，使皮下组织的血管破裂，血液聚积在皮下组织间，称皮下出血。
I've become good friends with several of the students in my school________I met in the English speech contest last year.
A．who
B．where
C．when
D．which
A．变小
B．变大
C．不变
D．先变小后变大
