下面哪项是电信服务的特点?()
A.有形性
B.生产过程与消费过程不可分
C.可存储转发
D.先付费,后服务
参考答案:B
— My office is untidy.
—You should spare some time to _________ the documents.
A.rely on
B.pick out
C.sort out
D.devote to