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.

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。

梁在荷载作用下产生挠度，梁端发生倾角，导致梁端有效支承长度（）梁端实际支撑长度。

梁在荷载作用下产生挠度，梁端发生倾角，导致梁端有效支承长度（）梁端实际支撑长度。

当梁在砌体上的实际支承长度a大于计算有效支承长度a0时，梁端砌体局部受压计算中应取（） 

由于梁跨内在竖向荷载作用下将产生弯曲变形，使得梁端局部受压砌体压应力分布不均匀，支座内边缘压缩变形大，且靠近梁端压缩变形越来越小，所以梁在墙上有效支承长度小于或等于实际支承长度。

逻辑运算符（AND、NOT、OR）的运算顺序是AND→OR→NOT。