证券交易的集中竞价应当实行（）的原则。A.价格优先.时间优先 B.大户优先 C.散户

在数轴上到－3的距离等于5的数是： （    ）

A．2

B．－8和－2

C．－2

D．2和－8

Basic Math introduces students to the basic things of mathematics, as well as some easy methods of learning it. These 30 fantastic courses are designed to provide students with understanding of arithmetic and to prepare them for Algebra (代数) and beyond.

　　The lessons in Basic Math cover every basic field of arithmetic. They also look into exponents (指数), the order of operations, and square roots. In addition to that, students also discover how a particular mathematical topic relates to other branches , and how they can be used practically.

　　Basic Math starts from easier concepts and gradually moves on to the more troublesome ones.  The lectures offer students the chance to understand of mathematical knowledge that may have seemed so frightening. They also help students prepare for college mathematics and develop confidence in this amazing field of study.

　　With the help of these lectures, they will be able to clear away the mystery (神秘性) of mathematics and face their studies with more confidence than they ever imagined. Besides, they will strengthen their ability to accept new and exciting mathematical challenges.

　　Professor H. Siegel, honored by Kentucky Educational Television as "the best math teacher in America, " is a devoted teacher and has a gift for explaining mathematical concepts in clear and interesting ways. From the basic ideas to the more difficult problems, he is a master in making math lectures learner-friendlier and less frightening

　　With a PhD in Mathematics Education form Georgia State University, Dr. Siegel now teaches mathematics at Central Arizona College.

　　If the course fails to provide complete satisfaction to you, you can easily exchange it for any other course that we offer. Or you can get your money back.

小题1:What does the course Basic Math mainly cover?

A．Algebra

B．College Mathematics

C．Arithmetic

D．Mathematics Education小题2: What good things can students expect from Basic Math?

A．Stronger imagination ability.

B．Additional presentation skills.

C．More mathematical confidence.

D．Greater chances of becoming teachers.小题3:What can we learn about Professor H. Siegel?

A．He is a lecturer at Kentucky Educational Television.

B．He is delivering 30 lectures in Basic Math.

C．He works in Georgia State University.

D．He specializes in training teachers.小题4:Where is the passage most likely to have been taken from?　　

A．news report

B．A book review

C．A lesson plan

D．An advertisement

客户销户时，应将剩余空白支票（），不得短缺，信用社对交回的空白支票应加盖“作废”戳记，作当日有关科目凭证附件。

A、带到信用社销毁

B、转至其它账户使用

C、自行剪角作废

D、交回信用社登记注销

摩擦性失业是指求职者在工作过程中与领导产生矛盾所出现的失业现象。

两个已知作物品种P1和P2作为亲本进行杂交，测得后代的抽穗期年平均值及方差如下表：
(1)不考虑互作遗传方差。请你写出关系式、计算抽穗期的广义遗传力和狭义遗传力。
(2)在可遗传的部分，有多大比例是可以稳定遗传的抽穗期遗传的平均显性程度是多大