不具有分裂能力的正常血细胞是（） A.早幼粒细胞 B.原始单核细

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问题单项选择题

不具有分裂能力的正常血细胞是（）

A.早幼粒细胞

B.原始单核细胞

C.早幼红细胞

D.中幼红细胞

E.网织红细胞

答案

参考答案：E

解析：在细胞发育过程中，晚幼以后阶段的细胞已丧失分裂能力，网织红细胞是晚幼红细胞脱核后形成的细胞。

阅读理解

缺词填空

Most children today go to a school where each class has its o 1 room. It was d 2 many years

ago. Most children w 3 to a one-room schoolhouse. In a one-room schoolhouse all the children learned

in one room from the s 4 teacher. A fourth grader might have sat next to a n 5 grader. Possibly you

have seen a one-room schoolhouse o 6 a television program.

There w 7 a good reason for many of the one-room schoolhouse. They were often in the

countryside, where there were o 8 ten to twenty children going to school. Then one room was big

e 9 for everyone! Today there are many m 10 children going to school. The one-room schoolhouse

has just about disappeared.

1. ________ 2. ________ 3. ________ 4. ________ 5. ________

6. ________ 7. ________ 8. ________ 9. ________ 10. ________

填空题

所有平台铁板铺设（），铁板表面应有（）以防滑跌。