There is a bookstore_____the second floor. [ ]
A. in
B. on
C. at
D. to
答案：B
有关消化系统放射性显像剂的选择
用于慢性、小量、活动性出血患者诊断消化道出血
A．99mTc-RBCB．99mTc-胶体C．Na99mTcO4D．99mTc-EHIDAE．99mTc-MAA
交往理性
