卵黄周隙
参考答案：
受精后，卵黄收缩，并在透明带和卵黄膜之间形成一个空隙，称之为卵黄周隙。
给句子重新排序，组成一段通顺的话。（提示已给出）
A. Tomorrow is Christmas.
B. We put up our Christmas tree.
C. It will be fun to talk to Santa in the store. He always says: Ho! Ho! Ho!
D. It's December twenty-fourth.
E. Li Ming and I are going to the department store this afternoon.
F. Yesterday we put Christmas lights on our house.
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闭路电视监控系统的规模可根据监视范围的大小以及监视目标的多少来确定，监视系统的大小一般根据摄像机的数量划分为，小于（）的为小型电视监控系统。
A.10个
B.15个
C.20个
D.30个
