被变质矿床
参考答案:原生矿床经过变质而形成一种变质矿床,但矿床有用组分的工业意义与工艺性质未发生改变,地质产状等也未发生明显改变的变质矿床。如沉积铁矿床变质成变质铁矿。
—Bob is ______ eight-year-old boy. But he knows a lot about Chinese history.
—How clever he is! [ ]
A. a
B. an
C. the
D. /
图像膜层是原版的核心部分,使原版保持较好的外观平整度和尺寸稳定性。