OSI 中，实现系统间二进制信息块的正确传输，为上一层提供可靠、无错误的数据信息的协议层是( )。
B
暂无解析
Thenewspaperwillhavetoclosedownifitcannotincreaseits________considerably.
WeenclosedourPurchaseConfirmationNo.4848__in__duplicate^)一式两份intriplicate(一式三份)
Traditionallinguistsbelievethatthewrittenformoflanguageis______tothespokenform.
Bythemiddleofthe21stcentury,thevastmajorityoftheworld’spopulationwillbelivingincities_______inthecountry.