关于绒毛膜的描述，正确者
A. 丛密绒毛膜与基蜕膜一起构成胎盘
B. 丛密绒毛膜与包蜕膜一起构成胎盘
C. 绒毛膜滋养层细胞过度增生，可出现葡萄胎
D. 绒毛间隙内充满了来自子宫螺旋动脉的母体血
E. 胚胎早期整个绒毛膜就有平滑绒毛膜和丛密绒毛膜之分
Up to now, we ______________ (not receive) any news from her.
I have worked here since I __________ (graduate) from college.
I already knew the sun ___ (be) the center of the solar system.
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