金属材料随着温度变化而膨胀的性能称为（）。
参考答案：热膨胀性
Have you heard the news ________ a highspeed railway between Huangshan and Hangzhou will be
under construction soon?[ ]
A. that
B. which
C. whether
D. whatever
变压器绕组绝缘的损坏原因有哪些？
