设计厚度加上材料厚度负偏差之后向上圆整到材料标准规格厚度后标注在图样上的厚度称为（）
A、名义厚度
B、有效厚度
C、计算厚度
D、以上都不对
参考答案：A
关于万有引力和万有引力定律理解正确的有( )
A．由知，两物体间距离r减小时，它们之间的引力增大，紧靠在一起时，万有引力非常大
B．由知, m1与m2受到的引力总是大小相等，方向相反的，是一对平衡力
C．不能看作质点的两物体之间不存在万有引力
D．引力常量G是由实验测得的，而不是人为规定的
Isabella Travelli, CFA, is a research analyst for Worldwide Investments in Rome, Italy. Travelli was contacted by Seaside Partners of Milan, Italy, a regional brokerage firm, about doing research on companies in the beverage industry on a contract basis. Travelli may only do the contract work:（）
A. after receiving consent from both Worldwide and Seaside.
B. if Worldwide has no clients in the same geographic area as Seaside.
C. if Worldwide does not follow the beverage industry.
