连续牵引车运转时()采用手动制动闸施闸。
A、可以
B、禁止
参考答案:B
The plane hasn't arrived yet. Could you tell me _____? [ ]
A. why the plane is late
B. how is the plane late
C. when will the plane arrive
D. that the plane arrives
赫克斯海默尔反应(赫氏反应)