短听力练习-7-17听录音，并选择正确选项
A. CES234 is maintaining at 2100m.
B. CES234 is able to cross CHat 55
CES234 is unable to cross CH before 55.
D. CES234 is able to comply with the controller’s instruction.
短听力练习-7-18听录音，并选择正确选项
A. due conflicting traffic.
B. due adverse weather
C. due level bust
D. due VIP flight
短听力练习-7-19听录音，并选择正确选项
A. Engine failed
B. Engine flamed out
C. Engine fire
D. Engine feathered
汽油机用起动机电压为（ ）伏
A. 6
B. 12
C. 24
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