出口商品运输包装容器生产企业质量许可证的有效期为( )年，出口商品的运输包装容器的

Should students make friends on line?some people think the Internet help make 1.______

many friends .Chatting online ,students can express his feelings          2.______

and opinions more freely ,and even get help at their foreign 3.______

language studies Others ,therefore ,think students should not . 4.______

They say making friends online is waste of time , 5.______  

which should be spent more meaningfully on study . 6.______

Besides ,some students get cheat on line .   7.______

It is my opinion whether students should place their study，8.______

health and safe before other things . 9.______

After all ,we can find friend in our classmates.. 10.______

治疗经行头痛的常用方剂下列哪些是正确的（）

A.羚角钩藤汤

B.半夏白术天麻汤

C.八珍汤

D.杞菊地黄丸

E.通窍活血汤

为保证滴丸圆整、丸重差异小，正确的是（）.

A、滴制时保持恒温

B、滴制液静压恒定

C、滴管口径合适

D、及时冷凝

在计算某投资项目的财务内部收益率时，得到以下结果：当用i=18%试算时，净现值为-400元；当用i=16%试算时，净现值为9元，则该项目的财务内部收益率为( )。

A．17.8%

B．17.96%

C．16.04%

D．16.20%

美国内战的背景和历史意义是什么