金属型铸造
参考答案：
用重力浇注将熔融金属浇入金属铸型获得铸件的方法。
辨析题：“恶是历史发展的动力”。
The Instruction Register (IR) is normally used to point out( ).
A．the address of next execution instruction
B．the address of last execution instruction
C．the current execution instruction
D．none of above
