非标准债权的主要风险有（）。
A.信用风险
B.操作风险
C.市场风险
D.政策风险
参考答案：A, B, C, D
Doctor Nathan is said to have been ________ to researching into wild animals in Africa for more than
ten years.[ ]
A. absorbed
B. devoted
C. concentrated
D. engaged
