个人商务贷款业务实行的原则包括（）。
A.额度控制
B.灵活使用
C.有效担保
D.按期偿还
参考答案：A, B, C, D
It's ten years since the scientist ___on his life's work of discovering the valuable chemical.[ ]
A. made for
B. set out
C. took off
D. turned up
简述猩红热诊断要点。
