When the circular-section low-carbon steel specimen is tensed until rupture, the gauge distance is changed from 100mm to 130mm, and the diameter is changed from 10mm to 7mm, then the Poisson rat io is .
【简答题】请将这句话 The transmission allows the gear ratio between the engine and the drive wheels to change as the car speeds up and slows down. You shift gears so the engine can stay below the redline and near th...