依据干尸治疗的原理，能干尸保留的是（）。
A.感染的牙髓
B.感染的冠髓
C.成形的根髓
D.坏死的牙髓
E.以上都不是
参考答案：C
Woman: I’ve changed my mind and would like to take the new approach.
Man: You’re on the right track now!
Question: What does the man mean().
A. The woman is right.
B. The woman is getting on well.
C. The woman is doing the right thing.
D. The woman has changed her mind.
什么是互检信号？如何显示？
