神经管的神经上皮()。
A.为假复层柱状上皮
B.基膜较厚,称外界膜
C.细胞不断分裂增殖
D.分化为成神经细胞和成神经胶质细胞
参考答案:A, B, C, D
A.激光
B.红外线
C.超声波
D.电磁波
I think we ______ be able to have holidays on the moon in about twenty years' time.
[ ]
A. are going to
B. will
C. can
D. would