进入老年期后，人的十大生理系统机能都有所下降。
A. 错误
B. 正确
CCA101identified10miles__theairfield（）
A. southwest of
B. to southwestern
C. the southwestern of
D. to southwest of
CCA101,reducespeedto230knotsdue（）
A. separation
B. sequencing
C. flow control
D. all of above
ACKNOWLEDGE”means（）
A. let me know that you have received this message
B. let me know that you have understood this message
C. let me know that you have received and understood this message
D. let me know whether you received this message
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