测得某线路二次功率值与实际二次值相比明显偏小,其可能的原因是()。
A.电压互感器(TV)电压缺相
B.某相电流被短接
C.变送器辅助电源故障
D.远动终端设备死机
参考答案:A, B
根据对话内容,在空缺处填上适当的单词。
Danny: Hello! Is that Jenny?
Jenny: Yes. 1. is Jenny speaking. Who's that?
Danny: Danny is 2. . May I ask you a funny question?
Jenny: Yes, you may. 3. is it?
Danny: What does the big chimney (烟囱) say to the little chimney?
Jenny: Sorry. I don't 4. .
Danny: He says, "You're too 5. to smoke (吸烟)."
Jenny: Haha, Wonderful!
下列哪些是食管癌的手术禁忌证()
A.病程较长,有梗阻者
B.全身情况差,恶病质
C.有远处转移
D.有严重心、肝、肾功能不全者
E.病变侵犯范围大,已有明显穿孔现象