7、当遭遇严重颠簸和/或者山地波导致的多大的高度偏差时，飞行员应向管制员报告“由于颠簸，不能保持RVSM”? How much altitude deviation caused by severe turbulence and/or mountain wave should the pilot report to controller “UNABLE RVSM DUE TO TURBULENCE”?
A.约45米（150英尺）或以上 45 meters (150feet) or above;
B.约60米（200英尺）或以上 60 meters (200feet) or above;
C.约90米（300英尺）或以上 90 meters (300feet) or above;
正确答案是B