体液酸碱平衡的调节主要通过（） A.化学缓冲系统 B.心血管系统 C.呼吸系统 D.

1999年10月2日，A市甲商贸公司将盖有本单位公章的介绍信和空白合同书以及10万元定金交给公司职员楚某，委托其到相邻B市的乙商场购买空调100台，声明每台定价不得超过4000元。10月3日，楚某找到乙商场，出具了甲商贸公司的已填上购买空调内容的介绍信和空白合同书，声称欲与乙商场签订一份100台空调的购销合同。乙商场经过审查，认为楚某出具的介绍信及空白合同书均盖有甲商贸公司的公章，且真实无误，遂确信其有代理权。经过一番磋商，乙商场坚持空调的最低价为每台4200元，楚某觉得甲商贸公司仍有利可图，便应允成交，由甲商贸公司向乙商场购买空调100台，单价为每台4200元，并于当日支付定金10万元，乙商场应该代办托运，并于10月7日交货，10月10日付款。双方还约定，如果任何一方违约，都要向对方支付7万元违约金。签约后，乙商场即组织货源，在10月6日将货交给B市第三运输公司承运，运货途中，第三运输公司司机韩某发现空调美观，便私自拿出一台以4200元的价格卖给了搭车同去A市的表弟史某，货按时到达甲商贸公司。10月12日，韩某将4200元款交给了甲商贸公司，甲商贸公司确认了买卖合同效力的合法性。10月14日，甲商贸公司以楚某签订合同超越当初所授权的价格为由拒绝支付“超出”部分的货款，为此乙商场诉至法院，要求甲商贸公司偿付拖欠的货款及逾期付款的违约金。问：

如果乙商场要求甲商贸公司付款，甲商贸公司能否主张买卖合同无效为什么

Co在化合物中呈现的价态类似于铁。已知Co(OH)₂在空气中加热时，固体残留率随温度的变化如图所示。已知钴的氢氧化物加热至290℃时已完全脱水。下列说法正确的是

A．290~ 500℃变化过程中的反应属于非氧化还原反应

B．500~1 000℃过程中的所有变化均不会有电子转移

C．290~ 500℃变化过程中Co的价态由低价变为高价

D．500～1 000℃变化过程中Co的价态由高价变为低价

第三部分 阅读理解（共20小题；每小题2分，满分40分）

阅读下列短文，从每题所给的四个选项（A、B、C和D）中，选出最佳选项，并在答题卡上将该项涂黑。

The engineer Camillo Olivetti was 40 years old when he started the company in 1908. At his factory in lvera, he designed and produced the first Italian typewriter. Today the company’s head office is still in Ivrea, near Turin, but the company is much lareer than it was in those days and there are offices all around the world.

By 1930 there was a staff of 700 and the company turned out 13,000 machines a year. Some went to customers in Italy, but Olivetti exported more typewriters to other countries.

Camilllo’s son, Adriano, started working for the company in 1924 and later he became the boss. He introduecd a standard speed for the production line and he employed technology and desion specialists. The company developed new and better typewriters and the calculators（计算器）.In 1959 it prodyced the ELLA computer system. This was the first mainframe（主机）computer designed and brade in Italy.

After Adriano died in 1960, the company had a period of financial problems. Other companies, especially the Janpanese, made faster progress in electronic technology than the Italian company.

In 1978, Carlo de Benedetti became the new boss. Olivetti increased its marking and service networks and made agreements with other companies to design and produce more advanced office equipment. Soon it became one, of the world’s leading companies in informationg technology and communications. There are now five independent companies in the Olivetti group --- one for personal computers,one for other office equipment, one for systerms and servicse, and two for telecommunications.

1.From the text we learn that__________.

A.by 1930 Olivetti produced 13,000 typewriters a year

B. Olivetti earned more in the 1960s than in the 1950s

C.some of Olivetti,s 700 staff regularly visited customers in Italy

D. Olivetti set up offices in other countries from the very beginning

2.What was probably the direct result of Olivetti,s falling behind in electronic technology?

A.A dtiano’s death.              B.A period of financial problem

C.its faster progress             D.Its agreements with other companies

3.What do we know about Olivetti ?

A.It produced the best typewriter in the word.

B.It designed the word’s first mainframe computer.

C.It exported more typewriter than other computer.

D.It has five independent companies with its head office in lvrea.

4.The best title for the text would be___________.

A.The Origin of Olivetti                    B.The Success of Olivetti

C.The History of Olivetti                   D.The Producich of Olivetti

SVG图形遵守的语法是（）。

A.XML语法

B.VC语法

C.Java语法

D.txt文件

简述锉削时的安全注意事项。