下面()是物流信息的管理需要考虑的信息特征。
A.相关性
B.对环境的适应性
C.集成性
D.层次性
参考答案:C
Only when he was refused by the interviewer ________ the importance of knowing English.
A.did he realize
B.he realized
C.had he realized
D.was he realized
用燃气灶烧水,燃烧0.1kg的煤气,使10kg的水从20℃升高到70℃.已知水的比热容为4.2×103J/(kg•℃),煤气的热值为4.2×107J/kg.求:
(1)0.1kg煤气完全燃烧放出的热量.
(2)水吸收的热量.
(3)燃气灶烧水的效率.