信贷担保的范围主要包括（）。
A.信贷业务的本金
B.信贷业务的利息
C.信贷业务的违约金
D.信贷业务的罚息
参考答案：A, B, C, D
医疗输液导管的灭菌可采用（）
A.煮沸消毒
B.干烤灭菌
C.压力蒸汽灭菌
D.紫外线消毒
E.电离辐射灭菌
Tom has been out of work for two years, so he has difficulty _____. [ ]
A. earning living
B. earning his living
C. to earn livings
D. to earn his living
