与按订单生产相比，备货型生产具有的特点之一是（）
A.产品库存占用较小
B.产品属非标准产品
C.产品属专用产品
D.产品属标准产品
参考答案：D
完成英语句子
1. (有)two maps and some pictures on the wall.
2. Her father (没有) any sister.
3. (有) some water in the cap.
4. —What's his (爸爸的) job?
—He is a teacher.
5. I can see (十九) students in the classroom.
6. Tom's school is a beautiful school and it's (英语) school.
用浓硫酸做脱水剂制备环己烯时，如果你的实验产率太低，试分析主要在哪些操作步骤中造成损失？
