液力传动当外载荷突然增大时，车辆能（）而增加牵引力。
参考答案：自动降速
胰腺主胰管直径（）
A.1mm
B.2.0mm
C.3.5mm
D.4.0mm
E.5.0mm
Who are talking [A] Two students. [B] Two policemen. [C] Two tourists.
