7. Person A: Pamela, can you come to a meeting on Friday?
Person B: ________ Let me check my schedule. When are you having it?
3.亚硝酸盐进入机体后,可使血中低铁血红蛋白氧化成高铁血红蛋白,从而失去输送氧的功能,致使组织缺氧。