CRH1隧道模式的作用及特点是什么?
参考答案:
用于动车组在通过隧道时,防止外部不良空气进入车厢内影响车内的空气质量,此时HVAC空调系统的废排风门关闭,回风风门打开。
— What do you think of teaching, Bob?
— I find it fun and challenging. It is a job _____ you are doing something serious but interesting. [ ]
A. where
B. which
C. When
D. that
已知a、b、c、d四项工作的逻辑关系如下表表示,正确反映该逻辑关系的网络图是()
A.选项A
B.选项B
C.选项C
D.选项D