设S={a,b,c},T=(1,2,3},R1,R2,R3是S到T的二元关系,且R1={(a,1),(b,2),(c,2)}, R2={(a,1),(a,2)},R3={(a,1),(b,1),(c,1)},那么在这3个二元关系中,可定义为A到B的函数是
A. R1和R2
B. 只有R2
C. R1和R2
D. R2和R3
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患者男性,35岁,会阴部疼痛伴尿频、尿急、尿痛3天。查体:体温39℃心肺(-),腹部(-),尿道外口无分泌物,指肛检查前列腺略肿大饱满,有触痛。血Rt:WBC 14×100/L,N78%,尿Rt:WBC许多/HP,RBC5~7/HP,B超前列腺略增大,形体饱满,边缘欠清晰,内部回声减轻但较均匀。最可能的疾病是()
A. 前列腺增生症伴感染
B. 非淋菌性尿道炎
C. 淋菌性尿道炎
D. 急性前列腺炎
E. 慢性细菌性前列腺炎
We thank you for your letter of May 5th,() your purchase from us of 5000 tons Green Beans.
A. confirm
B. to confirm
C. confirming
D. confirmed
This offer is ____ your reply reaching us before May 5th.
A. subject
B. subjected
C. subject to
D. subjected to
市场利率与债券价格成______变化,债券到期时间越长,利率风险( )
A. 反比越小
B. iE比越大
C. 正比越小
D. 反比越大