以下各题都是基于以下的叙述。 已知关系R与关系S如下图所示。 对R与S进行并运算

路面上导向箭头是何含义？（）

A．提示前方有左弯或需向左合流

B．提示前方有右弯或需向右合流

C．提示前方有障碍需向左合流

D．提示前方有左弯或需向左绕行

（）是指由纳税人依据账簿记载先自行计算缴纳，事后经税务机关查账核实，如有不符合税法规定的，则多退少补的一种税款征收方式。

A.查账征收

B.查定征收

C.定期定额征收

D.查验征收

（）发明了电池。

A．伽伐尼

B．伏特

C．奥斯特

D．法拉第

阅读理解。

     下面文章中有5处(第1~5题)需要添加小标题。请从以下选项(A、B、C、D、E和F)中选出符合各段意思的小标题，选项中有一项是多余选项。

A. Learn to Evaluate Data Correctly

B. Learn to Speak Clearly and Persuasively

C. Learn to Make Decisions Quickly and Properly

D. Learn to Relax Timely

E. Learn to Use Internet Efficiently

F. Learn to Express Yourself Effectively

Top Tips on How to Succeed in Life

What does it take to succeed in life? Author Dustin M. Wax has compiled a list of the top five skills you

need for a successful life.

1._________

Good writing skills are essential for today's competitive job market. But writing well isn't just a case of

producing grammatically correct sentences - it involves an ability to organize your thoughts, as well as

being able to target your ideas to an audience in the most effective way possible.

2.__________

With so much information out there, you need to be able to sort the potentially valuable data from the

trivial, to analyze its relevance and meaning, and to relate it back to other information.

3. ___________

Analyzing information is all very well, but at some stage you also need to make a decision. Over-analyzing can lead to hesitation, so you need to learn how to respond quickly and effectively, and to know what to

do based on the information available.

4. __________

You don't have to know everything, but you should be able to find out what you need to know quickly

and painlessly. This means learning how to use the internet effectively, how to read productively, and how

to draw on your network of contacts efficiently.

5. __________

Being able to switch off is extremely hard for some people, but you need to find time for exercise or ways of relieving stress and tension, or the pressure could end up literally killing you!

炉喉高度起到（）与（）两方面的作用。