（）is a space system using one or more artificial earth satellites.

Since the burning or combustion takes place within the engine itself, the engine is known as （）.

It should be apparent that little or nothing is gained by opening a drain at the same time as or after admitting steamThe above sentence probably means （）.

Project（71）is an uncertain event or condition that，if it occurs，has a positive or a negative effect on at least one project objective，such as time，cost，scope，or quality．

Project ______is an uncertain event or condition that，if it occurs，has a positive or a negative effect on at least one project objective，such as time，cost，scope，or quality．

● Project（71）is an uncertain event or condition that, if it occurs, has a positive or a negative effect on at least one project objective, such as time, cost, scope, or quality.（71）

 ______ 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.

If necessary to avoid collision or allow more time to（）the situation，a vessel shall slacken her speed or take all way off by stopping or reversing her means of propulsion．

A c（） sentence contains two or more clauses， one of which is incorporated in the other.

A salvor may be（）the whole or part of the payment due under Salvage Convention to the extent that the salvage operations have become necessary or more difficult because of fault or neglect on his part or if the salvor has been guilty of fraud or other dishonest conduct.

A mark or place at which a vessel comes under obligatory entry，transit，or escort procedure is know as（）.

Damage to cargo caused by fumes or vapors from liquids，gases，or solids is known as（）.