对于地面效应,以下哪些说法是对的? About ground effect, Which of the following statements are true?
A、机翼升力线斜率增加 Wing lift-curve slope increases.
B、平尾升力线斜率增加 Tail lift-curve slope increases.
C、中性点前移 Neutral point moves forward.
D、下洗角增加 Downwash angle increases.
E、飞机重心前限后移 Most forward CG location moves aftward.