外贸公司跟单和生产企业跟单的主要区别是( )。
A．生产进度跟单
B．选择产品供应商
C．包装跟单
D．品质跟单
参考答案：B
Passage One
How did interracial marriage get approved in Alabama a. By a Supreme Court ruling. b. By state legislation. c. By a vote of the residents. d. By the social trend that interracial marriages keep increasing.
“与其他建筑物的防火间距”属于（）的安全评价内容
A、压力容器
B、特种设备
C、仪表与自控系统
D、周边环境
