当油冷式X射线机机头内有气泡和缺油时会发生什么现象？
参考答案：
机头内有气泡时，送高压后，mA表针不规律的抖动或剧烈摆一下后，高压自动切断。
— Who is your favorite singer.Julia?
一 Well, it's hard to say. I like singers _____ write their own lyrics. [ ]
A. who
B. whose
C. which
D. what
外阴和 * * 炎症的共同特点是 * * 分泌物增加及外阴瘙痒。
