为应付可能发生的突发事件，经警队要实行（）住宿制度。
参考答案：轮流集中
商业性汇率风险是在国际贸易中因为汇率变动而遭受的风险。 ( )
How does Walter get along with his new business().
A.He has failed in business again.
B.His new company is doing rather well.
C.He hopes to succeed in business.
