航空器使用导航设备分散飞行,速度在450千米/小时以下,航迹夹角大于90度,过台时间不少于()分钟,可以相互穿越或占用同一高度。
A.3
B.5
C.10
D.15
参考答案:A
They asked the government to make _____ clear to the public _____ they did was right. [ ]
A. it; that what
B. it; that
C. that; what
D. this; that
为调节因环境温度变化而引起燃气管道的膨胀与收缩,在长管段上通常设置()。
A.套筒式补偿器
B.波形管补偿器
C.方形补偿器
D.Z字形补偿器