-I don't know how to write the article assigned by our professor on international trade.   

-You should have ______ your attention on the lecture that ______ how international situation affects

exports and imports across the globe.    [ ]

A. put; concentrate on  

B. paid; talked about    

C. fixed; dealt on  

D. focused; focused on

Flash中action“print”意义是？（）

A.鼠标触发条件

B.动画片段符号的事件触发程序

C.控制桢的播放

D.输出到打印机