ATPL: Which degree of aircraft turbulence is determined by the following ICAO description?'There may be moderate changes in aircraft attitude and/or altitude but the aircraft remains in positive control at all times. Usually, small variations in air speed. Changes in accelerometer readings of 0.5 to 1.0 g at the aircraft's centre of gravity. Occupants feel strain against seat belts. Loose objects move about. Food service and walking are difficult.'