绒毛膜固定组织是（）
A.初级干绒毛
B.次级干绒毛
C.三级干绒毛
D.细胞滋养层壳
E.细胞滋养层细胞柱
参考答案：D
用所给单词的适当形式填空。
1. Mr. Brown is in white _____(shoe) today.
2. Put_____(they) over there, please.
3. I think it's_____(Joy) sweater.
4. There _____(be) two old kites on the wall.
5. We don't know _____(she) name.
A．力越大，功率越大
B．距离越长，功率越大
C．做功越多，功率越大
D．做功越快，功率越大
