润滑油的粘度随着温度的升高而（），随压力的增高而

A.增大，降低

B.降低，增大

C.增大，变化不大

D.变化不大，降低

气体的粘度随压力增高而增高。在低压时，气体粘度随温度升高而增加，随着压力的增加，温度升高对粘度增大的影响越来越小，当压力很高时（100×105Pa以上），气体粘度随温度升高而降低，明显表现出类似于液体的性质。Table 1-13 shows the dynamic viscosity of methane at different pressures and temperatures. It can be seen from the table that the viscosity of gas increases with the increase of pressure. At low pressure, the gas viscosity increases with the increase of temperature. With the increase of pressure, the influence of temperature increase on the increase of viscosity becomes smaller and smaller. When the pressure is very high (100×105Pa and above), the gas viscosity decreases with the increase of temperature, showing obvious properties similar to liquid.

A.升高

B.不变

C.降低

D.不一定