测量绝缘介质损tgδ能反映绝缘本身状态，同时又能反映绝缘由良好状态向劣化状况转化过程。
参考答案：对
— What a fine day! Shall we go picnicking?
— ____. But we need to be home before six o'clock for the football match. [ ]
A. Have a nice time
B. Pardon me
C. That's great
D. You are right
甲状腺未分化癌是（）
A.最常见的甲状腺良性肿瘤
B.最常见的甲状腺恶性肿瘤
C.恶性度最高的甲状腺肿瘤
D.可分泌5-羟色胺和降钙素
E.恶性度中等且以血行转移为主
