______ twice a year, whether it is a car or a bus or a truck, is the rule that every driver must obey in this city.

The guard, fencing or shielding for moving parts or machinery can be removed for repair only when the machinery it belongs to（）

Scientists say it may be five or six years _____ this medicine is tested on human beings.

It will be a relief over the death of a friend or a relative if the friend or relative dies from ______.

The goal, which they are unlikely to live to see , is tocure, prevent or manage all diseasesin the next 80or so years.

Every deliberate act of wrongdoing by the master or any of the crew against the ship or cargo，without the authorization or privity of the Shipowner or his agent，is（）.

（）, or drum is used for hauling in or letting out the wires or ropes which will fasten the ship to the shore.

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.

逻辑运算符（AND、NOT、OR）的运算顺序是AND→OR→NOT。

Never（）the lifeboat or lifecraft disengaging locks or hydrostatic release gears because it can cause them to fail to function.

Never（）the lifeboat or lifecraft disengaging hocks or hydrostatic release gears because it can cause them to fail to function.

逻辑运算符（AND、NOT、OR）的运算顺序是AND→OR→NOT。