涌水量的产生主要有自然和人为两大因素。自然因素包括气候条件、地表水体、地形条件、（）

“教师节”快要到了，张爷爷欲用120元钱，为“光明”幼儿园购买价格分别为8元、6元和5元的图书20册．

（1）若设8元的图书购买x册，6元的图书购买y册，求y与x之间的函数关系式．

（2）若每册图书至少购买2册，求张爷爷有几种购买方案？并写出y取最大值和y取最小值时的购买方案．

2010年5月1日开幕的上海世博会，围绕“城市，让生活更美好”这一主题展示人类对“和谐城市”，“和谐生活”的追求与实践。上海世博会将成为人类文明进程中的一次精彩对话：它将成为全人类相互之间理解、沟通、欢聚、合作的大舞台，不同文明要在多样中求同一，在差异中求和谐，在交流中求发展。

试用唯物辩证法的相关知识说明“上海世博会将成为人类文明进程中的一次精彩对话”的理由。

____________________________________________________________________________________________________________________

National Geographic Society

17 TH and M Streets N.W., Washington D.C．20036 U.S.A.

The year is 1991．But just for a moment you will feel the centuries roll back.

Close your eyes and you can almost see Charlemagne kneeling to receive his crown as Holy Roman Emperor.

Or an ageing Michelangelo standing in the middle of rubble （碎石）, staring at the still unbuilt, sky-size dome （圆顶大厦）above.

You are in St. Peter’s Basilica, heart of one of the most attractive nations in the world …

Dear friend,

Every now and then, you visit a place that leaves a lasting impression – and memories that remain long after you’ve returned home. The Vatican is one of those unforgettable places.

As a devoted traveler, I have always believed that there is no replacement for being there. That is, before I saw National Geographic’s new volume （书卷）with my own eyes.

Inside the Vatican

In some ways it’s better than being there. Two experienced Geographic staff members – award-winning photographer James Stansfield and writer Bart Mcdowell – show you a side of the Vatican that you could never see if you were to visit as an ordinary tourist.

You’ll view sights and treasures that only a few are ever allowed to observe, and have extraordinary opportunity to be close to the Vatican’s museums and ceremonies, and to the people who live and work there.

Examine this magnificent volume – free in your home

You’re invited to reserve this attractive new volume now. Simply return the enclosed Reservation Card and your edition will be shipped for your free examination.

Send no money. I’m confident that once you see this amazing book, you won’t be able to put it down! INSIDE THE VATICAN offers you and your family many hours of delight and attraction.

With no risk, and no requirement to buy, why not take a moment now while you’re thinking of it – and mail the enclosed card?

We look forward to having you join us on this unusual journey.

Sincerely,

Michela English

P.S. Remember, too, that this beautiful volume is a perfect gift for anyone who loves travel, history, or art. But it’s available only by direct order through the society.

53．The part before the letter ________.

A．describes ancient Roman Emperor Charlemagne

B．introduces Vatican City, the independent state in Europe

C．tells about the famous Italian scientist and artist Michelangelo

D．gives an imaginary picture of the grandness of National Geographic Society

54．‘Dear Friend’ is used as a greeting because the writer ________.

A．and the reader know each other very well

B．and the reader have heard about each other

C．would like the reader to trust her

D．would like to get to know the reader

55．What the writer introduces to the reader is based on the volume’s ________.

A．quality of presentation           B．importance of sales

C．historical value                 D．value to collectors

56．The book will appeal to ________.

A．the recipient （接受者）         B．the recipient, his wife and children

C．art historians                   D．traveling salesmen

用于检测血清转氨酶

A．谷氨酸脱氢酶
B．胆红素氧化物酶
C．α-羟类固醇脱氢酶
D．乳酸脱氢酶
E．甘油激酶

某密闭容器中加入0．3 mol A、0．1 mol C和一定量的B三种气体。一定条件下发生反应，各物质浓度随时间变化如图甲所示［t₀～t₁阶段c（B）未画出］。图乙为t₂后改变互不相同的某一条件反应速率随时间变化的关系图，t₃～t₄阶段使用了催化剂。下列说法错误的是（   ）

A．若t₁＝15 s，生成物C在t₀～t₁时间段的平均反应速率为 0．004mol·L^－1·s^－1

B．t₄～t₅阶段改变的条件为减小压强，t₅～t₆改变的条件是升高化学反应的温度

C．B的起始物质的量为0．02mol

D．该化学反应的表达式为：3A B + 2C