亮亮向东北走了50米,他因有事转向西南走了50米,他最后回到了原地。[ ]
正确
She can't us because her mother is ill. [ ]
A. joining
B. joined
C. join
D. to join
高性能飞机的驾驶员应该注意当下滑坡度比正常的VASI下滑坡度大时,可能导致什么后果?