缺词填空（本题共10小题，每小题1分，共10分）

Most children today go to a school where each class has its o 小题1: room. It was d 小题2: many years ago. Most children w 小题3:to a one-room schoolhouse. In a one-room schoolhouse all the children learned in one room from the s 小题4: teacher. A fourth grader might have sat next to a n  小题5: grader. Possibly you have seen a one-room schoolhouse o 小题6: a television program.

There w 小题7: a good reason for many of the one-room schoolhouse. They were often in the countryside, where there were o 小题8:ten to twenty children going to school. Then one room was big e 小题9:for everyone! Today there are many m 小题10: children going to school. The one-room schoolhouse has just about disappeared.

（）是年入库总量或年出库总量与年平均库存之比。

A.库房高度利用率

B.仓库有效容积

C.仓库周转次数

D.仓容利用率