When the renewal verification is completed more than three months before the expiry date of the existing Document of Compliance or Safety Management Certificate, the new Document of Compliance or the new Safety Management Certificate should be valid from the date of （） for a period not exceeding five years.

60.  A from time to time   B  in time    C  sooner or later   D on occasion

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）

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

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 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.

Jitter is an unwanted variation of one or more characteristics of a periodic signal in electronics and telecommunications and（）refers to call issues that cause variations in timing or time of arrival.

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

The ball _____ two or three times before rolling down the slope.