设a=2，b=3，c=4，d=5，下列表达式的值是（ ）。 3>2*b Or a=c And bc Or ba+c

采用ADC0809构成模拟量输入通道，ADC0809在其中起（）作用。

ADC0809的START引脚需要加一个（），才能启动ADC0809开始转换。

单片机ADC0809的功能是（）。

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

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（）.

在51系列单片机应用系统中读取ADC0809的转换结果时，使用________指令。

在51系列单片机应用系统中启动ADC0809进行A/D转换时，使用________指令。