判断题 按转换能量的方式，可以将话筒分为动圈式话筒和电容式话筒。

未知题型 Proponents of rational expectations argue that failing to account for peoples" revised inflation expectations led to estimates of the sacrifice ratio that were too high

单项选择题 对于双组分系统，平衡时系统最多可有（ ）相平衡共存。