苏轼、黄庭坚、米芾、蔡襄是我国______代四大书法家。( )
A.汉
B.晋
C.唐
D.宋
参考答案:D
肿瘤由混乱排列的牙组织成分组成,但无典型牙齿
A.组合性牙瘤 B.混合性牙瘤 C.牙源性钙化上皮瘤 D.牙源性腺样瘤 E.牙源性钙化囊肿
________ classroom is very big and clean.
A.They
B.There
C.Their
D.Them