Vessels must be（）valid certificate of nationality or certificated of registry or license.

When loading or discharging dry mud or cement，crew members should use goggles and（）.

Effects which are dutiable or subject to prohibitions or restrictions should be declared in （）.

The（）may examine or re-examine the goods or take samples from them straightaway in the absence of the consignee or the consignor whenever it considers this necessary.

（）are liable to be stoten, pilfered or may damaged due to improper handing or stowage.

在用示波器测量信号波形时，要使输出波形稳定，则要使扫描周期是被测信号周期的（）倍。

Banks have no liability for any delay or loss caused by postal or telex failure.

逻辑运算符（AND、NOT、OR）的运算顺序是AND→OR→NOT。

电子示波器是一种常用的电子仪器，它可以观察电信号的波形，通过屏幕显示直接测量信号的（）、（）和相位参数，还可以测量脉冲信号的前后沿、脉宽、上冲、下冲等参数。

用示波器测量波形时，信号随车速波形越密集电压幅值（）。

●设AND、OR和NOT分别表示按位与、按位或和按位求反运算，且X=10011011，Y=01111010，Z=11101000，则(NOT(X) AND Y)= (9) ， (Y OR NOT(Z))= (10) 。10011011011110101110100001100000(10)

逻辑运算符（AND、NOT、OR）的运算顺序是AND→OR→NOT。