主族元素W、X、Y、Z的原子序数依次增大，W的原子最外层电子数是次外层电子数的3

下列几种传染病中病程最短的是（）

A.口蹄疫

B.结核病

C.牛流行热

D.牛病毒性腹泻

E.牛传染性鼻气管炎

在下列句子中，哪一个句子中的“以”字解释为“按照”（ ）。

A．是社稷之臣也，何以伐为？

B．皆以力战为名。

C．斧斤以时入山林。

D．却宾客以业诸侯。

SECTION C

Directions: Complete the following passage by filling in each blank with ONE word that best fits the context.

How much paper do you use every year? Probably you can’t answer this question quickly. In 1900,the world’s use of paper was about one kilogram  48  each person in a year. Now some countries use as  49 as 50 kilograms of paper for each person in a year. The amount of paper a country uses shows how far advanced the country is, some people say. It is difficult to say  50  this is true: different people mean different things  51  the word “advanced”. But countries like the United States, England and Sweden certainly use    52   paper than other countries.

Paper, like many other things that we use today, was first made in China. In Egypt and the West, paper was not very commonly used before   53  year 1400.The 54  wrote on papyrus; Europeans used parchment for many hundreds of years. Parchment was very strong ;   55  was made from the skin of a certain young animal. We have learnt some of the most important facts of European history from record that were kept on parchment.

有关 * * 的叙述，下列正确的是（）

A. * * 位于膀胱、 * * 和直肠之间

B. * * 开口于前庭后部

C.环官颈的 * * 上段形成 * * 穹隆

D. * * 前壁比后壁长

E.后穹隆顶端为子宫直肠凹陷底部

CO可用于合成甲醇，一定温度下，向体积为2L的密闭容器中加入CO和H₂，发生反应CO（g）+2H₂（g）⇌CH₃OH（g），达平衡后测得各组分浓度如下：

物质	CO	H2	CH3OH
浓度（mol•L-1）	0.9	1.0	0.6

①混合气体的平均相对分子质量______．

②列式并计算平衡常数K=______．

③若将容器体积压缩为1L，不经计算，预测新平衡中c（H₂）的取值范围是______．

④若保持体积不变，再充入0.6molCO和0.4molCH₃OH，此时v_正______v_逆（填“＞”、“＜”“=”）．