I am very tired today. I _____ go to bed early.[ ]
A. should
B. shouldn't
C. can
D. can't
答案:A
栓塞中最常见类型为
A.血栓栓塞
B.脂肪栓塞
C.羊水栓塞
D.气体栓塞
E.瘤细胞栓塞
债券交易品种包括()
A、回购
B、转让
C、现券买卖
D、贴现