永久性听阈位移包括()
A.听觉适应、听觉疲劳
B.听觉疲劳、听觉损伤
C.听觉适应、噪声性耳聋
D.听力损伤、噪声性耳聋
E.听觉疲劳、噪声性耳聋
参考答案:D
经过几年的不懈努力,截至2010年3月,我国高速铁路运营里程居世界第()位。
A.1
B.2
C.3
D.4
All ships which, in accordance with the present Convention, are required to carry radio installations shall carry().
A.Q-code
B.Telephone numbers and addresses
C.the international Codes of Signals
D.radio instructions