Упражнение 56. Переведите следующие предложения

1. Efficiency at each speed is relatively constant, there being little overlapping at the high levels of pressure ratio tested. 2. Low temperature tests were performed with the specimen completely submerged in liquid nitrogen (76 K) or liquid helium (4 K) environments. 3. This indicates that the present model is relevant and suitable for predicting the severity of ring bore contact for varying engine operating and lubrication conditions. 4. The stress analysis is influenced by the fact that concrete is much weaker even in little tension than in compression.