炎症时巨噬细胞的主要作用是()
A.释放血管活性胺
B.修复损伤的组织
C.转变为浆细胞
D.吞噬病原微生物和坏死组织碎片
E.参与机体免疫反应
参考答案:D
Was it _____ he was playing volleyball on the playground _____ he got hurt? [ ]
A. that; when
B. when; that
C. that; where
D. where; that
为什么变压器原边电流是由副边决定的?