国际上通用的控制对外贸易的非关税措施有（）A.配额 B.许可证 C.外汇控制 D.名

荧光分光光度法测定维生素B时，激发光和发射光波长分别是（）

A.440nm和525nm

B.450nm和550nm

C.480nm和530nm

D.490nm和525nm

E.445nm和540nm

1919年，发源于北京的反帝反封建的爱国运动：                             。

女性，21岁，因原发性甲亢在颈丛麻醉下行甲状腺大部切除术，术后12h病人颈前有压迫感，呼吸困难，发绀，切口敷料呈红色，颈部肿胀，应立即（）。

A.给氧

B.松解敷料

C.气管内插管加压给氧

D.剪断缝线，敞开切口，清除血肿

E.气管切开

Have you ever heard your own voice "Of course," you say.
Has anyone else ever heard your voice Again you say, "Of course. "
But that’ s not quite true. Nobody else has ever heard your voice—the way you hear it. When you talk, you set up sound waves. The air outside your head carries the sound waves to your outer ears. But, of course, the sound of your voice begins inside your head. The bones of your head pick up the sound waves, too. They carry the sound waves straight to your inner ears. You get the sound from the outside and the inside too. Other people get just the sound waves from the outside. That’s why they don’t hear your voice the way you do.

Sound travels in the form of ______.

A．bones

B．air

C．waves

D．voice

（）无助于加强计算机的安全。

A.安装杀毒软件并及时更新病毒库

B.及时更新操作系统补丁包

C.把操作系统管理员帐号的口令设置为空

D.安装使用防火墙