在施工中遇到安全无保证措施作业时，有权拒绝作业，同时立刻报告有关部门，这是建筑工人的安全职责。( )
参考答案：对
Mr. Smith returned from China last week, taking ______vase. [ ]
A. a Chinese old interesting pottery
B. an old interesting pottery Chinese
C. an pottery old interesting Chinese
D. an interesting old Chinese pottery
简析内部规模经济与产业内贸易的关系。
