后牙临床牙冠与固定义齿功能直接有关的是()
A.连接强度
B.固位力
C.支持力
D.美观性
E.舒适度
参考答案:B
---- Do you know our town at all?
---- No, this ______ the first time I ______ here.
A.was; has come
B.is; come
C.is; had come
D.is; have come
简述我国传统科技的民族文化基础。