超声波的入射角（ ）。
A、大于反射角C
暂无解析
Thevolunteerswouldrathergobytrainthan________.
Theengineer______myfatherworksisabout50yearsold.
Canyouofferusmachinetools___thefollowingspecification?
Linguistscanconcentrateonalltheaspectsoflanguageatonce.
______movesonascaleofthenationallanguage,dialects,andindividualwaysofcommunication.
