()适合于大件小批、高新技术等产品或大项目、大工程企业和新产品开发。
参考答案:矩阵制
The products described above have been subjected to ( ) treatment of at least 80ºC for 30 minutes.
A. freeze
B. cold
C. heat
D. wash
棉花根属于()系,由主根,侧根,支根毛根及根毛构成。