x线片根尖周透射区包括数牙时确诊病源牙的主要依据是患牙()。
A.有无龋洞
B.有无窦道
C.牙髓有无活力
D.是否有牙周疾病
E.有无叩痛
参考答案:C
按要求完成句子
1. I was three years old when I started doing the things.(对画线部分提问)
_____ _____ _____ you when you started doing the things?
2. I went to the zoo last Sunday.(对画线部分提问)
What _____ _____ _____ last Sunday?
3. I saw some sharks.(改为一般疑问句)
_____ you _____ _____ sharks?
4. The students had a terrible school trip.(改为否定句)
The students _____ _____ a terrible school trip.
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