Java程序中定义接口所使用的关键字是【 】。
参考答案:interface
解析:接口的定义为[访问权限]interface接口名[extends父类接口]{…}。
复数z=cos75°+isin75° (i是虚数单位),则在复平面内z2对应的点位于第______象限.
Many students listened to the lecture, but I wondered how much work they took________. [ ]
A. out
B. up
C. off
D. in