光纤通信按通信业务种类可分为计算机网和()。
A、分组交换网B
暂无解析
Hismotherbecomesdisappointedwheneverhefailstoliveuptoher________(expect)
Justafewyearsago，Tanyawas___(home)andbeggingformoneyinfrontofasupermarketinNewYorkCity.
一质点做匀变速圆周运动时，其（）
Peopletodayarehighlyconcernedaboutthequalityoftheairthey___(breath).
Youmayusebike________yougiveitbacktometomorrowmorning
