窦房结位于 ( ) 窦房结位于 ( )A.下腔静脉入口处的心外膜深面B.上腔静脉口前方的心内膜深面C.上腔静脉与右心耳交界处的心外膜深面D.房间隔下部的心内膜深面E.以上都不正确 分类:习题答案 题型:选择题 查看答案
According to the passage, growing lab meat is technically difficult because_____ According to the passage, growing lab meat is technically difficult because _________A. meat is a tis 分类:习题答案 题型:选择题 查看答案