库血保存时间不超过（）.
A.3天
B.1周
C.3周
D.4周
E.5周
参考答案：C
解析：目前常用抗凝剂CPD和ACD抗凝血可保存21天。
选出下列各句的答语，写在相应的位置上。
They are Ken's.
They are 8 yuan.
It's 16 yuan.
It's Danny's. Thank you.
Yes, it is.
1. Here's the money._____________________
2. Is this your ruler? ____________________
3. How much is the doll? _________________
4. Whose CDs are these? ________________
5. How much are the pencils? _____________
6. Whose book is it? ___________________
企业实施ISO9000系列标准的目的是（）。
A.提高企业的知名度
B.提高企业的管理水平
C.提高工人的素质
D.提高企业的经济效益
