设a=′′a′′，b=′′b′′，c=′′c′′，d=′′d′′，执行语句x=IIf（（ad），′′A′′，′′B′′）后，x的值为（　　）。

In speaking activities, a speaker often tries to avoid using a difficult word or structure and chooses to use a simpler one. What learning strategy does the speaker use?

In speaking activities,a speaker often tries to avoid using a difficult word or structure and chooses to use a simpler one. What learning strategy does the speaker use?

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

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

—Do you learn Russian or French?—I learn _____.

—Do you learn Russian or French?—I learn ______.

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）

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（）.