PC微球面研磨抛光，电信运营商的设备中应用得最为广泛；APC呈（）角并做微球面研磨抛光。
A.6度
B.7度
C.8度
D.9度
参考答案：C
—Why is Peter working so hard these days?.
—The _______ of failing the exam next week makes him do so.
A．announcement
B．threat
C．competence
D．dilemma
The extension of the time of shipment will facilitate our ______ the goods.
A．preparing B．preparednessC．readiness D．ready
