液相反应法合成纳米粒子——溶胶凝胶法，其基本原理

Lots people stress out（紧张） about talking in front of the class or getting laughed at if they make a mistake in front of an audience._71_ The “stress hormones” that your body produces at times like these can actually help you focus.

But when worry and stress about performing get to be too much, these hormones give people that “red alert(紧急状态)”---the one that causes you to feel cold or sweaty, or get butterflies in your stomach._72__

Be prepared. __73_ Rehearse(排练) as much as you can and practice in front of others at every opportunity. Most of all, think positively. Tell yourself “I’ll be OK” or “I can do this” even if you are not 100% sure of it.

Look after yourself. Before big performances, it’s easy to let taking care of yourself slip as you spend too much time on rehearsals and practice. __74__ Exercise can also can also help you feel good, and along with sleep and nutrition, is an excellent way of keeping those stress hormones from getting out of control.

Find out what the experts do. You can find books, DVD, and online information about how to give your best when you perform, depending on what type of performance you’re preparing for._75_ Or ask the cast of your school play or your drama or music teacher how they beat stage fright. And if your parents or grandparents ever performed, they may have their own secrets to share.

A Confidence helps beat stress hormones.

B The following tips can help you avoid that feeling.

C You’re less likely to freeze up if you’re well prepared.

D You can do this whether you’re performing alone or as part of a group.

E Check out stories about Olympic gymnasts or your favorite star to get their tips.

F Feeling nervous before a performance is part of body’s way of helping you do your best.

G You’ll look and feel your best if you get enough sleep and eat healthy meals before your performance.

“这一发现使工业几乎彻底摆脱地方条件所规定的一切界限，并且使极遥远的水力的利用成为可能。”“这一发现”是指

A．蒸汽机的发明

B．电的利用

C．蒸汽轮船的发明

D．内燃机的发明

发绀伴呼吸困难见于（）（）。

下面关于误码的描述，正确的是（）

A.误码是指经接收、判决、再生后，数字码流中的某些比特发生了差错

B.SDH系统中，可以通过B1、B2、B3分别对再生段、复用段和高阶通道的误码情况进行检测

C.B1、B2、B3只能检测一块中奇数个数的误码，偶数个误码无法检测出来

D.SDH系统可以根据B1、B2、B3的监测结果对信号误码进行纠错

男，52岁，因患十二指肠球部溃疡合并幽门不全梗阻入院施行胃大部切除术。术中出血约600ml，心率92次/分，呼吸21次/分，血压13.1/8.0kpa(98/60mmHg)，血红蛋白105g/L。在输血问题上，正确做法是

A．输注晶体液补充血容量，原则上不输血
B．输全血600ml补充丢失的失血量
C．输血浆和红细胞各300ml代替丢失的全血
D．输红细胞悬液600ml，不必输注全血
E．输血浆600ml补充血容量，不必输注红细胞